Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit

ABSTRACT

An image forming apparatus includes a process cartridge. The process cartridge includes a coupling member having a first end portion, a second end portion, and a connecting portion connecting the first end portion and the second end portion. The second end portion of the coupling member includes at least one pair of projections, with each of the projections includinga facing portion that faces the axis L 2 , each facing portion being open to the axis L 2 . A maximum dimension in a direction perpendicular to the axis L 2  of at least a part of the connecting portion is smaller than a diameter of an imaginary circle that is tangent to the facing portions of the projections.

FIELD OF THE INVENTION AND RELATED ART

The present invention relates to a process cartridge, anelectrophotographic image forming apparatus to which the processcartridge is detachably mountable, and an electrophotographicphotosensitive drum unit.

Examples of the electrophotographic image forming apparatus include anelectrophotographic copying machine, an electrophotographic printer (alaser beam printer, an LED printer, and so on), and the like.

The process cartridge is prepared by integrally assembling anelectrophotographic photosensitive member and process means acting onthe electrophotographic photosensitive member into a unit (cartridge)and is mounted to and demounted from a main assembly of theelectrophotographic image forming apparatus. For example, the processcartridge is prepared by integrally assembling the electrophotographicphotosensitive member and at least one of a developing means, a chargingmeans, and a cleaning means as the process means into a cartridge.Accordingly, examples of the process cartridge include a processcartridge prepared by integrally assembling the electrophotographicphotosensitive member and three process means consisting of thedeveloping means, the charging means, and the cleaning means into acartridge; a process cartridge prepared by integrally assembling theelectrophotographic photosensitive member and the charging means as theprocess means into a cartridge; and a process cartridge prepared byintegrally assembling the electrophotographic photosensitive member andtwo process means consisting of the charging means and the cleaningmeans.

The process cartridge is detachably mountable to an apparatus mainassembly by a user by himself (herself). Accordingly, maintenance of theapparatus can be performed by the user by himself without relying on aservice person. As a result, operability of the maintenance of theelectrophotographic image forming apparatus.

In a conventional process cartridge, the following constitution forreceiving a rotational driving force, for rotating a drum shapedelectrophotographic photosensitive member (hereinafter referred to as a“photosensitive drum”), from an apparatus main assembly is known.

On a main assembly side, a rotatable member for transmitting a drivingforce of a motor and a non circular twisted hole, which is provided at acenter portion of the rotatable member and has a cross sectionintegrally rotatable with the rotatable member and provided with aplurality of corners, are provided.

On a process cartridge side, a non circular twisted projection, which isprovided at one of longitudinal ends of a photosensitive drum and has across section provided with a plurality of corners, is provided.

When the rotatable member is rotated in an engaged state between theprojection and the hole in the case where the process cartridge ismounted to the apparatus main assembly, a rotational force of therotatable member is transmitted to the photosensitive drum in a state inwhich an attraction force toward the hole is exerted on the projection.As a result, the rotational force for rotating the photosensitive drumis transmitted from the apparatus main assembly to the photosensitivedrum (U.S. Pat. No. 5,903,803). Further, a method in which aphotosensitive drum is rotated by engaging a gear fixed to thephotosensitive drum constituting a process cartridge has been known(U.S. Pat. No. 4,829,335).

However, in the conventional constitution described in U.S. Pat. No.5,903,803, the rotatable member is required to be moved in a horizontaldirection when the process cartridge is mounted to or demounted from themain assembly by being moved in a direction substantially perpendicularto an axial line of the rotatable member. That is, the rotatable memberis required to be horizontally moved by an opening and closing operationof a main assembly cover provided to the apparatus main assembly. By theopening operation of the main assembly cover, the hole is moved apartfrom the projection. On the other hand, by the closing operation of themain assembly cover, the hole is moved toward the projection so as to beengaged with the projection.

Accordingly, in the conventional process cartridge, a constitution formoving the rotatable member in a rotational axis direction by theopening and closing operation of the main assembly cover is required tobe provided to the main assembly.

In the constitution described in U.S. Pat. No. 4,829,335, without movingthe driving gear provided to the main assembly along the axial linedirection thereof, the cartridge can be mounted to and demounted fromthe main assembly by being moved in a direction substantiallyperpendicular to the axial line. However, in this constitution a drivingconnection portion between the main assembly and the cartridge is anengaging portion between gears, so that it is difficult to preventrotation non uniformity of the photosensitive drum.

SUMMARY OF THE INVENTION

A principal object of the present invention is to provide a processcartridge, a photosensitive drum unit used in the process cartridge, andan electrophotographic image forming apparatus to which the processcartridge is detachably mountable, capable of solving the abovedescribed problems of the conventional process cartridges.

Another object of the present invention is to provide a processcartridge capable of smoothly rotating a photosensitive drum by beingmounted to a main assembly provided with no mechanism for moving a mainassembly side coupling member, in its axial line direction, fortransmitting a rotational force to the photosensitive drum by an openingand closing operation of a main assembly cover. A further object of thepresent invention is to provide a photosensitive drum unit used in theprocess cartridge and an electrophotographic image forming apparatus towhich the process cartridge is mountable and from which the processcartridge is demountable.

A further object of the present invention is to provide a processcartridge demountable from a main assembly of an electrophotographicimage forming apparatus provided with a driving shaft in a directionperpendicular to an axial line of the driving shaft. A further object ofthe present invention is to provide a photosensitive drum unit used inthe process cartridge and an electrophotographic image forming apparatusto which the process cartridge is detachably mountable.

A further object of the present invention is to provide a processcartridge mountable to a main assembly of an electrophotographic imageforming apparatus provided with a driving shaft in a directionsubstantially perpendicular to an axial line of the driving shaft. Afurther object of the present invention is to provide a photosensitivedrum unit used in the process cartridge and an electrophotographic imageforming apparatus to which the process cartridge is detachablymountable.

A further object of the present invention is to provide a processcartridge mountable to and demountable from a main assembly of anelectrophotographic image forming apparatus provided with a drivingshaft in a direction substantially perpendicular to an axial line of thedriving shaft. A further object of the present invention is to provide aphotosensitive drum unit used in the process cartridge and anelectrophotographic image forming apparatus to which the processcartridge is detachably mountable.

A further object of the present invention is to provide a processcartridge which compatibly realized that the process cartridge isdemountable from a main assembly provided with a driving shaft in adirection substantially perpendicular to an axial line of the drivingshaft and is capable of smoothly rotating the photosensitive drum. Afurther object of the present invention is to provide a photosensitivedrum unit used in the process cartridge and an electrophotographic imageforming apparatus to which the process cartridge is detachablymountable.

A further object of the present invention is to provide a processcartridge which compatibly realizes that the process cartridge ismountable to a main assembly provided with a driving shaft in adirection substantially perpendicular to an axial line of the drivingshaft and is capable of smoothly rotating the photosensitive drum. Afurther object of the present invention is to provide a photosensitivedrum unit used in the process cartridge and an electrophotographic imageforming apparatus to which the process cartridge is detachablymountable.

A further object of the present invention is to provide a processcartridge which compatibly realizes that the process cartridge ismountable to and demountable from a main assembly provided with adriving shaft in a direction substantially perpendicular to an axialline of the driving shaft and is capable of smoothly rotating thephotosensitive drum. A further object of the present invention is toprovide a photosensitive drum unit used in the process cartridge and anelectrophotographic image forming apparatus to which the processcartridge is detachably mountable.

According to the present invention, there is provided a processcartridge which can be demounted from a main assembly of anelectrophotographic image forming apparatus provided with the driveshaft in a direction substantially perpendicular to an axis of a driveshaft

According to the present invention, there is provided a photosensitivedrum unit usable with the process cartridge and an electrophotographicimage forming apparatus to which the process cartridge is detachablymountable

According to the present invention, there is provided a processcartridge mountable, in a direction substantially perpendicular to anaxis of a drive shaft, to a main assembly of an electrophotographicimage forming device provided with the drive shaft

According to the present invention, there is provided a photosensitivedrum unit usable with the process cartridge and an electrophotographicimage forming apparatus with the detachably mountable process cartridge

According to the present invention, there is provided a processcartridge which can be mounted and dismounted, in a directionsubstantially perpendicular to an axis of a drive shaft, to a mainassembly of an electrophotographic image forming apparatus provided withthe drive shaft

According to the present invention, there is provided a photosensitivedrum unit usable with the process cartridge and an electrophotographicimage forming apparatus relative to which the process cartridge can bemounted and demounted

According to the present invention, a process cartridge is mounted to amain assembly which is not provided with a mechanism for moving a mainassembly side drum coupling member for transmitting a rotational forceto a photosensitive drum to an axial direction, and can rotate thephotosensitive drum smoothly

According to the present invention, a process cartridge can be demountedin a direction substantially perpendicular to an axis of a drive shaftprovided in a main assembly, and simultaneously, the smooth rotation ofa photosensitive drum can be carried out

According to the present invention, a process cartridge can be mountedin a direction substantially perpendicular to an axis of a drive shaftprovided in a main assembly, and simultaneously, the smooth rotation ofa photosensitive drum can be carried out

According to the present invention, a process cartridge is mountable anddismountable in a direction substantially perpendicular to an axis of adrive shaft provided in a main assembly, and simultaneously, the smoothrotation of a photosensitive drum can be carried out.

These and other objects, features, and advantages of the presentinvention will become more apparent upon consideration of the followingdescription of the preferred embodiments of the present invention, takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional side elevation of a cartridge according to anembodiment of the present invention.

FIG. 2 is a perspective view of the cartridge according to theembodiment of the present invention.

FIG. 3 is a perspective view of the cartridge according to theembodiment of the present invention.

FIG. 4 is a sectional side elevation of an apparatus main assemblyaccording to the embodiment of the present invention.

FIG. 5 is a perspective view and a longitudinal sectional view of a drumflange (drum shaft) according to the embodiment of the presentinvention.

FIG. 6 is a perspective view of a photosensitive drum according to theembodiment of the present invention.

FIG. 7 is longitudinal sectional views of the photosensitive drumaccording to the embodiment of the present invention.

FIG. 8 is perspective views and a longitudinal sectional view of acoupling according to the embodiment of the present invention.

FIG. 9 is perspective views of a drum bearing member according to theembodiment of the present invention.

FIG. 10 is detailed views of a side surface of the cartridge accordingto the embodiment of the present invention.

FIG. 11 is exploded perspective views and longitudinal sectional viewsof the coupling and the bearing member according to the embodiment ofthe present invention.

FIG. 12 is a longitudinal sectional view after the assembling of thecartridge according to the embodiment of the present invention.

FIG. 13 is a longitudinal sectional view after the assembling of thecartridge according to the embodiment of the present invention.

FIG. 14 is a longitudinal sectional view of the cartridge according tothe embodiment of the present invention.

FIG. 15 is perspective views which illustrate a combined state of thedrum shaft and the coupling.

FIG. 16 is perspective views which illustrate an inclined state of thecoupling.

FIG. 17 is perspective views and a longitudinal sectional view of adriving structure of the apparatus main assembly according to theembodiment of the present invention.

FIG. 18 is a perspective view of a cartridge set portion of theapparatus main assembly according to the embodiment of the presentinvention.

FIG. 19 is a perspective view of the cartridge set portion of theapparatus main assembly according to the embodiment of the presentinvention.

FIG. 20 is sectional views which illustrate a process of the mounting ofthe cartridge to the apparatus main assembly according to the embodimentof the present invention.

FIG. 21 is perspective views which illustrate a process of theengagement between the drive shaft and the coupling according to theembodiment of the present invention.

FIG. 22 is perspective views which illustrate a process of theengagement between the drive shaft and the coupling according to theembodiment of the present invention.

FIG. 23 is perspective views which illustrate the coupling of theapparatus main assembly and the coupling of the cartridge according tothe embodiment of the present invention.

FIG. 24 is an exploded perspective view which illustrates the driveshaft, the driving gear, the coupling, and the drum shaft according tothe embodiment of the present invention.

FIG. 25 is perspective views which illustrate a process of thedisengagement of the coupling from the drive shaft according to theembodiment of the present invention.

FIG. 26 is perspective views which illustrate the coupling and the drumshaft according to the embodiment of the present invention.

FIG. 27 is perspective views which illustrate the drum shaft accordingto the embodiment of the present invention.

FIG. 28 is perspective views which illustrate a drive shaft and adriving gear according to the embodiment of the present invention.

FIG. 29 is perspective views which illustrate the coupling according tothe embodiment of the present invention, and side views.

FIG. 30 is exploded perspective views which illustrate the drum shaft,the drive shaft, and the coupling according to the embodiment of thepresent invention.

FIG. 31 shows a side view and a longitudinal section of the side surfaceof the cartridge according to the embodiment of the present invention.

FIG. 32 is a perspective view and a view, as seen from the device of thecartridge set portion of the apparatus main assembly, according to theembodiment of the present invention.

FIG. 33 is longitudinal sectional views which illustrate a dismountingprocess from the apparatus main assembly of the cartridge according tothe embodiment of the present invention.

FIG. 34 is longitudinal sectional views which illustrate a mountingprocess to the apparatus main assembly of the cartridge according to theembodiment of the present invention.

FIG. 35 is perspective views which illustrate phase control means for adrive shaft according to a second embodiment of the present invention.

FIG. 36 is perspective views which illustrate a mounting operation of acartridge according to the embodiment of the present invention.

FIG. 37 is perspective views of a coupling according to the embodimentof the present invention.

FIG. 38 is top plan views of a mounted state of the cartridge as seen ina mounting direction according to the embodiment of the presentinvention.

FIG. 39 is perspective views which illustrate a drive stop state of theprocess cartridge (photosensitive drum) according to the embodiment ofthe present invention.

FIG. 40 is longitudinal sectional views and perspective views whichillustrate a dismounting operation of the process cartridge according tothe embodiment of the present invention.

FIG. 41 is a sectional view which illustrates the state where a doorprovided in an apparatus main assembly is opened according to a thirdembodiment of the present invention.

FIG. 42 is a perspective view which illustrates a mounting guide of adriving side of the apparatus main assembly according to the embodimentof the present invention.

FIG. 43 is a side view of the driving side of the cartridge according tothe embodiment of the present invention.

FIG. 44 is a perspective view as seen from the driving side of thecartridge according to the embodiment of the present invention.

FIG. 45 is side view which illustrates an inserting state of thecartridge to the apparatus main assembly according to the embodiment ofthe present invention.

FIG. 46 is a perspective view which illustrates an attaching state of alocking member to a drum bearing member according to a fourth embodimentof the present invention.

FIG. 47 is an exploded perspective view which illustrates the drumbearing member, a coupling, and a drum shaft according to the embodimentof the present invention.

FIG. 48 is a perspective view which illustrates a driving side of thecartridge according to the embodiment of the present invention.

FIG. 49 is perspective views and longitudinal sectional views whichillustrate an engaged state between a drive shaft and a couplingaccording to the embodiment of the present invention.

FIG. 50 is an exploded perspective view which illustrates a state wherea pressing member was mounted to a drum bearing member according to afifth embodiment of the present invention.

FIG. 51 is exploded perspective views which illustrate the drum bearingmember, a coupling, and a drum shaft according to the embodiment of thepresent invention.

FIG. 52 is a perspective view which illustrates the driving side of acartridge according to the embodiment of the present invention.

FIG. 53 is perspective views and longitudinal sectional views whichillustrate an engaged state between a drive shaft and the couplingaccording to the embodiment of the present invention.

FIG. 54 is an exploded perspective view which illustrates a cartridgebefore assembling the major members according to a sixth embodiment ofthe present invention.

FIG. 55 is a side view which illustrates a driving side according to theembodiment of the present invention.

FIG. 56 is schematic longitudinal sectional views of a drum shaft and acoupling according to the embodiment of the present invention.

FIG. 57 is longitudinal sectional views which illustrate the engagementbetween a drive shaft and coupling according to the embodiment of thepresent invention.

FIG. 58 is sectional views which illustrate a modified example of acoupling locking member according to the embodiment of the presentinvention.

FIG. 59 is a perspective view which illustrates an attaching state of amagnet member to a drum bearing member according to a seventh embodimentof the present invention.

FIG. 60 is an exploded perspective view which illustrates the drumbearing member, a coupling, and a drum shaft according to the embodimentof the present invention.

FIG. 61 is a perspective view which illustrates a driving side of thecartridge according to the embodiment of the present invention.

FIG. 62 is perspective views and longitudinal sectional views whichillustrate an engaged state between a drive shaft and coupling accordingto the embodiment of the present invention.

FIG. 63 is a perspective view which illustrates the driving side of acartridge according to an eighth embodiment of the present invention.

FIG. 64 is n exploded perspective views which illustrate a state beforethe assembly of a bearing member according to the embodiment of thepresent invention.

FIG. 65 is longitudinal sectional views which illustrate the structuresof a drum shaft, a coupling, and a bearing member according to theembodiment of the present invention.

FIG. 66 is a perspective view which illustrates a driving side of anapparatus main assembly guide according to the embodiment of the presentinvention.

FIG. 67 is longitudinal sectional views which illustrate a disengagementstate of a locking member according to the embodiment of the presentinvention.

FIG. 68 is longitudinal sectional views which illustrate the engagementbetween a drive shaft and a coupling according to the embodiment of thepresent invention.

FIG. 69 is side views which illustrate a driving side of a cartridgeaccording to a ninth embodiment of the present invention.

FIG. 70 is a perspective view which illustrates a driving side of anapparatus main assembly guide according to the embodiment of the presentinvention.

FIG. 71 is side views which illustrate a relation between the cartridgeand the main assembly guide according to the embodiment of the presentinvention.

FIG. 72 is perspective views which illustrate a relation between themain assembly guide and the coupling according to the embodiment of thepresent invention.

FIG. 73 is side views, as seen from the driving side, which illustrate aprocess of the mounting to the main assembly of the cartridge, accordingto the embodiment of the present invention.

FIG. 74 is a perspective view which illustrates a driving side of a mainassembly guide according to a tenth embodiment of the present invention.

FIG. 75 is a side view which illustrates a relation between the mainassembly guide and a coupling according to the embodiment of the presentinvention.

FIG. 76 is a perspective view which illustrates a relation between themain assembly guide and the coupling according to the embodiment of thepresent invention.

FIG. 77 is a side view which illustrates a relation between thecartridge and the main assembly guide according to the embodiment of thepresent invention.

FIG. 78 is perspective views which illustrate a relation between themain assembly guide and the coupling according to the embodiment of thepresent invention.

FIG. 79 is a side view which illustrates a relation between the mainassembly guide and the coupling according to the embodiment of thepresent invention.

FIG. 80 is a perspective view which illustrates a relation between themain assembly guide and the coupling according to the embodiment of thepresent invention.

FIG. 81 is a side view which illustrates a relation between the mainassembly guide and the coupling according to the embodiment of thepresent invention.

FIG. 82 is a perspective view and a sectional view of a couplingaccording to an eleventh embodiment of the present invention.

FIG. 83 is a perspective view and a sectional view of the couplingaccording to the embodiment of the present invention.

FIG. 84 is a perspective view and a sectional view of the couplingaccording to the embodiment of the present invention.

FIG. 85 is perspective views and sectional views of a coupling accordingto a twelfth embodiment of the present invention.

FIG. 86 is perspective views which illustrate a coupling according to athirteenth embodiment of the present invention.

FIG. 87 is a sectional view which illustrates a drum shaft, a driveshaft, the coupling, and an urging member according to the embodiment ofthe present invention.

FIG. 88 is sectional views which illustrate the drum shaft, thecoupling, a bearing member, and the drive shaft according to theembodiment of the present invention.

FIG. 89 is a perspective view which illustrates a drum shaft and acoupling according to a 14th embodiment of the present invention.

FIG. 90 is perspective views which illustrate a process of theengagement between a drive shaft and coupling according to theembodiment of the present invention.

FIG. 91 is perspective views and sectional views which illustrate a drumshaft, a coupling, and a bearing member according to a 15th embodimentof the present invention.

FIG. 92 is perspective views which illustrate a supporting method for acoupling (mounting method) according to a 16th embodiment of the presentinvention.

FIG. 93 is perspective views which illustrate a supporting method for acoupling (mounting method) according to a 17th embodiment of the presentinvention.

FIG. 94 is a perspective view of a cartridge according to an embodimentof the present invention.

FIG. 95 illustrates only a coupling according to the embodiment of thepresent invention.

FIG. 96 illustrates a drum flange having a coupling according to anembodiment of the present invention.

FIG. 97 is sectional views taken along S22-S22 of FIG. 84.

FIG. 98 is a sectional view of a photosensitive drum unit according toan embodiment of the present invention.

FIG. 99 is a sectional view taken along S23-S23 of FIG. 85.

FIG. 100 is perspective views which illustrate a combined state of adrum shaft and a coupling according to an embodiment of the presentinvention.

FIG. 101 is perspective views which illustrate an inclined state of acoupling according to an embodiment of the present invention.

FIG. 102 is perspective views which illustrate a process of theengagement between a drive shaft and a coupling according to anembodiment of the present invention.

FIG. 103 is perspective views which illustrate a process of theengagement between a drive shaft and a coupling according to anembodiment of the present invention.

FIG. 104 is an exploded perspective view which illustrates a driveshaft, a driving gear, a coupling, and a drum shaft according to anembodiment of the present invention.

FIG. 105 is perspective views which illustrate a process of thedisengagement of a coupling from a drive shaft according to anembodiment of the present invention.

FIG. 106 is perspective views which illustrate a combined state betweena drum shaft and a coupling according to an embodiment of the presentinvention.

FIG. 107 is perspective views which illustrate a combined state betweena drum shaft and a coupling according to an embodiment of the presentinvention.

FIG. 108 is perspective views showing a combined state between a drumshaft and a coupling according to an embodiment of the presentinvention.

FIG. 109 is a perspective view of a first frame unit which has aphotosensitive drum, as seen from the driving side, according to anembodiment of the present invention.

FIG. 110 is a perspective view which illustrates a drum shaft and acoupling according to an embodiment of the present invention.

FIG. 111 is a sectional view taken along S20-S20 in FIG. 79.

FIG. 112 is a perspective view of a photosensitive drum unit accordingto an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The process cartridge and an electrophotographic image forming apparatusaccording to according to an embodiment of the present invention will bedescribed.

[Embodiment 1]

(1) Brief Description of Process Cartridge

A process cartridge B to which an embodiment of the present invention isapplied will be described with reference to FIGS. 1 to 4. FIG. 1 is asectional view of the cartridge B. FIGS. 2 and 3 are perspective viewsof the cartridge B. FIG. 4 is a sectional view of an electrophotographicimage forming apparatus main assembly A (hereinafter referred to as an“apparatus main assembly A”). The apparatus main assembly A correspondsto a portion of the electrophotographic image forming apparatus fromwhich the cartridge B is excluded.

Referring to FIGS. 1 to 3, the cartridge B includes anelectrophotographic photosensitive drum 107. The photosensitive drum 107is rotated by receiving a rotational force from the apparatus mainassembly A by a coupling mechanism when the cartridge B is mounted inthe apparatus main assembly A as shown in FIG. 4. The cartridge B ismountable to and demountable from the apparatus main assembly A by auser.

A charging roller 108 as a charging means (process means) is provided incontact with an outer peripheral surface of the photosensitive drum 107.The charging roller 108 electrically charges the photosensitive drum 107by voltage application from the apparatus main assembly A. The chargingroller 108 is rotated by the rotation of the photosensitive drum 107.

The cartridge B includes a developing roller 110 as a developing means(process means). The developing roller 110 supplies a developer to adeveloping area of the photosensitive drum 107. The developing roller110 develops an electrostatic latent image formed on the photosensitivedrum 107 with the developer t. The developing roller 110 containstherein a magnet roller (fixed magnet) 111. In contact with a peripheralsurface of the developing roller 110, a developing blade 112 isprovided. The developing blade 112 defines an amount of the developer tto be deposited on the peripheral surface of the developing roller 110.The developing blade 112 imparts triboelectric charges to the developert.

The developer t contained in a developer accommodating container 114 issent to a developing chamber 113 a by rotation of stirring members 115and 116, so that the developing roller 110 supplied with a voltage isrotated. As a result, a developer layer to which the electric chargesare imparted by the developing blade 112 is formed on the surface of thedeveloping roller 110. The developer t is transferred onto thephotosensitive drum 107 depending on the latent image. As a result, thelatent image is developed.

The developer image formed on the photosensitive drum 107 is transferredonto a recording medium 102 by a transfer roller 104. The recordingmedium 102 is used for forming an image of the developer thereon and,e.g., is recording paper, label, OHP sheet, and so on

In contact with the outer peripheral surface of the photosensitive drum107, an elastic cleaning blade 117 a as a cleaning means (process means)is disposed. The cleaning blade 117 a elastically contacts thephotosensitive drum 107 at its end and removes the developer t remainingon the photosensitive drum 107 after the developer image is transferredonto the recording medium 102. The developer t removed from the surfaceof the photosensitive drum 107 by the cleaning blade 117 a isaccommodated in a removed developer reservoir 117 b.

The cartridge B is integrally constituted by a first frame unit 119 anda second frame unit 120.

The first frame unit 119 is constituted by a first frame 113 as a partof a cartridge frame B1. The first frame unit 119 includes thedeveloping roller 110, the developing blade 112, the developing chamber113 a, the developer accommodating container 114, and the stirringmembers 115 and 116.

The second frame unit 120 is constituted by a second frame 118 as a partof the cartridge frame B1. The second frame unit 120 includes thephotosensitive drum 107, the cleaning blade 117 a, the removed developerreservoir 117 b, and the charging roller 108.

The first frame unit 119 and the second frame unit 120 are rotatablyconnected with each other by a pin P. By an elastic member 135 (FIG. 3)provided between the first and second frame units 119 and 120, thedeveloping roller 110 is pressed against the photosensitive drum 107.

The user attaches (mounts) the cartridge B to a cartridge mountingportion 130 a of the apparatus main assembly A by gripping a grip.During the mounting, as described later, a driving shaft 180 (FIG. 17)of the apparatus main assembly A and a coupling member 150 (describedlater) as a rotational force transmitting part of the cartridge B areconnected with each other in synchronism with the mounting operation ofthe cartridge B. The photosensitive drum 107 or the like is rotated byreceiving the rotational force from the apparatus main assembly A.

(2) Description of Electrophotographic Image Forming Apparatus

With reference to FIG. 4, the electrophotographic image formingapparatus using the above described cartridge B will be described.

In the following, a laser beam printer will be described as an exampleof the apparatus main assembly A.

During image formation, the surface of the rotating photosensitive drum107 is electrically charged uniformly by the charging roller 108. Then,the surface of the photosensitive drum 107 is irradiated with laserlight, depending on image information, emitted from an optical means 101including unshown members such as a laser diode, a polygonal mirror, alens, and a reflecting mirror. As a result, on the photosensitive drum107, an electrostatic latent image depending on the image information isformed. The latent image is developed by the above described developingroller 110.

On the other hand, in synchronism with the image formation, therecording medium 102 set in a cassette 103 a is conveyed to a transferposition by a feeding roller 103 b and conveying roller pairs 103 c, 103d and 103 e. At the transfer position, the transfer roller 104 as atransfer means is disposed. To the transfer roller 104, a voltage isapplied. As a result, the developer image formed on the photosensitivedrum 107 is transferred onto the recording medium 102.

The recording medium 102 onto which the developer image is transferredis conveyed to a fixing means 105 through a guide 103 f. The fixingmeans 105 includes a driving roller 105 c and a fixing roller 105 bcontaining therein a heater 105 a. To the passing recording medium 102,heat and pressure are applied, so that the developer image is fixed onthe recording medium 102. As a result, on the recording medium 102, animage is formed. Thereafter, the recording medium 102 is conveyed byroller pairs 103 g and 103 h and discharged on a tray 106. The abovedescribed roller 103 b, the conveying roller pairs 103 c, 103 d and 103e, the guide 103 f, the roller pairs 103 g and 103 h, and the likeconstitute a conveying means 103 for conveying the recording medium 102.

The cartridge mounting portion 130 a is a portion (space) for mountingthe cartridge B therein. In a state in which the cartridge B ispositioned in the space, the coupling member 150 (described later) ofthe cartridge B is connected with the driving shaft of the apparatusmain assembly A. In this embodiment, the mounting of the cartridge B tothe mounting portion 130 a is referred to as mounting of the cartridge Bto the apparatus main assembly A. Further, demounting (removal) of thecartridge B from the mounting portion 130 b is referred to as demountingof the cartridge B from the apparatus main assembly A.

(3) Description of Constitution of Drum Flange

First, a drum flange at a side where the rotational force is transmittedfrom the apparatus main assembly A to the photosensitive drum 107(hereinafter simply referred to a “drive side”) will be described withreference to FIG. 5. FIG. 5(a) is a perspective view of the drum flangeat the drive side and FIG. 5(b) is a sectional view of the drum flangetaken along S1-S1 line shown in FIG. 5(a). Incidentally, with respect toan axial line direction of the photosensitive drum, a side opposite fromthe drive side is referred to as a “non-drive side”).

A drum flange 151 is formed of a resinous material by ejection molding.Examples of the resinous material may include polyacetal, polycarbonate,and so on A drum shaft 153 is formed of a metallic material such asiron, stainless steel, or the like. Depending on a load torque forrotating the photosensitive drum 107, it is possible to selectappropriately the materials for the drum flange 151 and the drum shaft153. For example, the drum flange 151 may also be formed of the metallicmaterial and the drum shaft 153 may also be formed of the resinousmaterial. When both of the drum flange 151 and the drum shaft 153 areformed of the resinous material, they can be integrally molded.

The flange 151 is provided with an engaging portion 151 a which engageswith an inner surface of the photosensitive drum 107, a gear portion(helical gear or spur gear) 151 c for transmitting a rotational force tothe developing roller 110, and an engaging portion 151 d rotatablysupported on a drum bearing. More specifically, as for the flange 151,the engaging portion 151 a engages with one end of a cylindrical drum107 a as will be described hereinafter. These are disposed co-axiallywith a rotation axis L1 of the photosensitive drum 107. And, the drumengaging portion 151 a has a cylindrical shape, and a base 151 bperpendicular thereto is provided. The base 151 b is provided with adrum shaft 153 outwardly projected with respect to the direction of theaxis L1. This drum shaft 153 is co-axial with the drum engaging portion151 a. These are fixed so as to be co-axial with the rotation axis L1.As for the fixing method thereof the press-fitting, the bonding, theinsert molding, and so on are available, and they are selected properly.

The drum shaft 153 comprises the circular column portion 153 a which hasa projection configuration, and is disposed so as to be co-axially withthe rotation axis of the photosensitive drum 107. The drum shaft 153 isprovided on the end part of the photosensitive drum 107 on the axis L1of the photosensitive drum 107. In addition, the drum shaft 153 is about5-15 mm in diameter in consideration of the material, the load, and thespace. A free end portion 153 b of the circular column portion 153 a hasa semi-spherical surface configuration so that it can incline smoothly,when an axis of a drum coupling member 150 which is a rotating forcetransmitting portion inclines, as will be described in detailhereinafter. In addition, in order to receive the rotational force fromthe drum coupling member 150, a rotating force transmitting pin(rotating force receiving member (portion) 155 are provided on thephotosensitive drum 107 side of the free end of the drum shaft 153. Thepin 155 is extended in the direction substantially perpendicular to theaxis of the drum shaft 153.

The pin 155 as the rotational force receiving member has a cylindricalshape which has a diameter smaller than that of the circular columnportion 153 a of the drum shaft 153, and is made of the metal or theresin material. And, it is fixed by press-fitting, bonding, and so on tothe drum shaft 153. And, the pin 155 is fixed in the direction which theaxis thereof intersects the axis L1 of the photosensitive drum 107.Preferably, it is desirable to dispose the axis of the pin 155 so as topass the center P2 of the spherical surface of the free end portion 153b of the drum shaft 153 (FIG. 5 (b)). Although the free end portion 153b is the semi-spherical surface configuration actually, the center P2 isthe center of a phantom spherical surface that the semispherical surfacemakes the part thereof. In addition, the number of the pins 155 can beselected properly. In this embodiment, a single pin 155 is used from thestandpoint of the assembling property and in order to transmit drivingtorque assuredly. The pin 155 passes said center P2, and is through thedrum shaft 153. And, the pin 155 is outwardly projected at the positionsof the peripheral surface of the drum shaft 153 which are diametricallyopposite (155 a 1, 155 a 2). More particularly, the pin 155 is projectedin the direction perpendicular to the axis (axis L1) of the drum shaft153 relative to the drum shaft 153 at the two opposite places (155 a 1,155 a 2). By this, the drum shaft 153 receives the rotational force fromthe drum coupling member 150 at the two places. In this embodiment, thepin 155 is mounted to the drum shaft 153 in the range of 5 mm from thefree end of the drum shaft 153. However, this does not limit the presentinvention.

In addition, a space portion 151 e formed by the engaging portion 151 dand the base 151 b receives a part of drum coupling member 150, inmounting the drum coupling member 150 (which will be describedhereinafter) to the flange 151.

In this embodiment, the gear portion 151 a for transmitting therotational force to the developing roller 110 is mounted to the flange151. However, the rotation of the developing roller 110 may betransmitted not through the flange 151. In that case, the gear portion151 c is unnecessary. However, in the case of disposing the gear portion151 a at the flange 151, integral molding, with the flange 151, of thegear portion 151 a can be utilized.

The flange 151, the drum shaft 153, and the pin 155 function as therotational force receiving member which receives the rotational forcefrom the drum coupling member 150 as will be described hereinafter.

(4) Structure of Electrophotographic Photosensitive Member Drum Unit

Referring to FIG. 6 and FIG. 7, the structure of an electrophotographicphotosensitive member drum unit (“drum unit”) will be described. FIG. 6(a) is a perspective view, as seen from the driving side, of the drumunit U1, and FIG. 6 (b) is a perspective view as seen from thenon-driving side. In addition, FIG. 7 is a sectional view taken alongS2-S2 of FIG. 6 (a).

The photosensitive drum 107 has a cylindrical drum 107 a coated with aphotosensitive layer 107 b on the peripheral surface.

The cylindrical drum 107 a has an electroconductive cylinder, such asthe aluminum, and the photosensitive layer 107 b applied thereon. Theopposite ends thereof are provided with the drum surface and thesubstantially co-axial opening 107 a 1, 107 a 2, in order to engage thedrum flange (151, 152). More particularly, the drum shaft 153 isprovided on the end part of the cylindrical drum 107 a co-axially withthe cylindrical drum 107 a. Designated by 151 c is a gear and transmitsa rotational force which the coupling 150 received from a drive shaft180 to a developing roller 110. The gear 151 c is integrally molded withthe flange 15.

The cylinder 107 a may be hollow or solid.

As to the drum flange 151 of the driving side, since it has beendescribed in the foregoing, the description is omitted.

A drum flange 152 of the non-driving side is made of the resin materialsimilarly to the driving side with injection molding. And, a drumengaging portion 152 b and a bearing portion 152 a are substantiallyco-axially disposed with each other. In addition, the flange 152 isprovided with a drum grounding plate 156. The drum grounding plate 156is an electroconductive thin plate (metal). The drum grounding plate 156includes contact portions 156 b 1, 156 b 2 which contact the innersurface of the electroconductive cylindrical drum 107 a, and a contactportion 156 a which contacts the drum grounding shaft 154 (which will bedescribed hereinafter). And, for the purpose of grounding thephotosensitive drum 107, the drum grounding plate 156 is electricallyconnected with the apparatus main assembly A.

A drum flange 152 of the non-driving side is made of the resin material,similarly to the driving side with injection molding. And, a drumengaging portion 152 b and a bearing portion 152 a are substantiallyco-axially disposed with each other. In addition, the flange 152 isprovided with a drum grounding plate 156. The drum grounding plate 156is an electroconductive thin plate (metal). The drum grounding plate 156includes contact portions 156 b 1, 156 b 2 which contact the innersurface of the electroconductive cylindrical drum 107 a, and a contactportion 156 a which contacts the drum grounding shaft 154 (which will bedescribed hereinafter). And, for the purpose of grounding thephotosensitive drum 107, the drum grounding plate 156 is electricallyconnected with the apparatus main assembly A.

Although it has been described that the drum grounding plate 156 isprovided in the flange 152, the present invention is not limited to suchan example. For example, the drum grounding plate 156 may be disposed atthe drum flange 151, and it is possible to select properly the positionwhich can be connected with the ground.

Thus, the drum unit U1 comprises the photosensitive drum 107 which hasthe cylinder 107 a, the flange 151, the flange 152, the drum shaft 153,the pin 155, and the drum grounding plate 156.

(5) Rotational Force Transmitting Portion (Drum Coupling Member)

The description will be made, referring to FIG. 8 as to an example ofthe drum coupling member which is the rotational force transmittingportion. FIG. 8 (a) is a perspective view, as seen from the apparatusmain assembly side, of the drum coupling member, FIG. 8 (b) is aperspective view, as seen from the photosensitive drum side, of the drumcoupling member, and FIG. 8 (c) is a view seen in the directionperpendicular to the direction of the coupling rotation shaft L2. Inaddition, FIG. 8 (d) is the side view, as seen from the apparatus mainassembly side, of the drum coupling member, FIG. 8 (e) is the Figure, asseen from the photosensitive drum side, and FIG. 8 (f) is a sectionalview taken along S3 in FIG. 8 (d).

The drum coupling member (“coupling”) 150 engages with a drive shaft 180(FIG. 17) of the apparatus main assembly A in the state where thecartridge B is mounted set to the installation section 130 a. Inaddition, the coupling 150 is disengaged from the drive shaft 180, whenthe cartridge B is taken out from the apparatus main assembly A. And,the coupling 150 receives a rotational force from a motor provided inthe apparatus main assembly A through the drive shaft 180 in the statewhere it is engaged with the drive shaft 180. In addition, the coupling150 transmits the rotational force thereof to the photosensitive drum107. The materials available for the coupling 150 are the resinmaterials, such as polyacetal and the polycarbonate PPS. However, inorder to raise a rigidity of the coupling 150, the glass fibers, thecarbon fibers, and so on may be mixed in the above described resinmaterial correspondingly to a required load torque. In the case ofmixing said material, the rigidity of the coupling 150 can be raised. Inaddition, in the resin material, the metal may be inserted, then therigidity may further be raised, and the whole coupling may bemanufactured from the metal and so on.

The coupling 150 mainly comprises three portions.

The first portion is engageable with the drive shaft 180 (which will bedescribed hereinafter), and it is a coupling side driven portion 150 afor receiving the rotational force from the rotational forcetransmitting pin 182 which is a rotational force applying portion (mainassembly side rotational force transmitting portion) provided on thedrive shaft 180. In addition, the second portion is engageable with thepin 155, and it is a coupling side driving portion 150 b fortransmitting the rotational force to the drum shaft 153. In addition,the third portion is a connecting portion 150 c for connecting thedriven portion 150 a and the driving portion 150 b with each other(FIGS. 8 (c) and (f)).

The driven portion 150 a, the driving portion 150 b, and the connectingportion 150 c may be molded integrally, or, alternatively, the separateparts may be connected with each other. In this embodiment, these areintegrally molded with resin material. By this, the manufacturing of thecoupling 150 is easy and the accuracy as the parts is high. As shown inFIG. 8(f) the driven portion 150 a is provided with a drive shaftinsertion opening portion 150 m which expands toward the rotation axisL2 of the coupling 150. The driving portion 150 b has a drum shaftinsertion opening portion 1501. which expands toward the rotation axisL2.

The opening 150 m has a conical driving shaft receiving surface 150 f asan expanded part which expands toward the drive shaft 180 side in thestate where the coupling 150 is mounted to the apparatus main assemblyA. The receiving surface 150 f constitutes a recess 150 z as shown inFIG. 8 (f). The recess 150 z includes the opening 150 m at a positionopposite the side adjecent the photosensitive drum 107 with respect tothe direction of the axis L2.

By this, regardless of rotation phase of the photosensitive drum 107 inthe cartridge B, the coupling 150 can pivot among a rotational forcetransmitting angular position, a pre-engagement angular position, and adisengaging angular position relative to the axis L1 of thephotosensitive drum 107 without being prevented by the free end portionof the drive shaft 180. The rotational force transmitting angularposition, the pre-engagement angular position, and the disengagingangular position will be described hereinafter.

A plurality of projections (the engaging portions) 150 d 1-150 d 4 areprovided at equal intervals on a circumference about the axis L2 on anend surface of the recess 150 z. Between the adjacent projections 150 d1, 150 d 2, 150 d 3, 150 d 4, the standing-by portions 150 k 1, 150 k 2,150 k 3, 150 k 4 are provided. An intervals between the adjacentprojections 150 d 1-150 d 4 is larger than the outer diameter of the pin182, so that the rotational force transmitting pins of the drive shaft180 provided in the apparatus main assembly A (rotational force applyingportions) 182 are received. The recesses between the adjacentprojections are the standing-by portions 150 k 1-k 4. When therotational force is transmitted to the coupling 150 from the drive shaft180, the transmission pins 182 a 1, 182 a 2 are received by any of thestanding-by portions 150 k 1-k 4. In addition, in FIG. 8 (d), therotational force reception surfaces (rotational force receivingportions) 150 e crossing with a rotational direction of the coupling 150and (150 e 1-150 e 4) are provided in the downstream with respect to theclockwise direction (X1) of each projection 150 d. More particularly,the projection 150 d 1 has a receiving surface 150 e 1, the projection150 d 2 has a receiving surface 150 e 2, the projection 150 d 3 has areceiving surface 150 e 3, and, and, a projection 150 d 4 has areceiving surface 150 e 4. In the state where the drive shaft 180rotates, the pin 182 a 1, 182 a 2 contacts to any of the receivingsurface 150 e 1-150 e 4. By doing so, the receiving surface 150 econtacted by the pin 182 a 1, 182 a 2 is pushed by the pin 182. By this,the coupling 150 rotates about the axis L2. The receiving surface 150 e1-150 e 4 is extended in the direction crossing with the rotationaldirection of the coupling 150.

In order to stabilize the running torque transmitted to the coupling 150as much as possible, it is desirable to dispose the rotational forcereceiving surfaces 150 e on the same circumference that has the centeron the axis L2. By this, the rotational force transmission radius isconstant and the running torque transmitted to the coupling 150 isstabilized. In addition, as for the projections 150 d 1-150 d 4, it ispreferable that the position of the by coupling 150 is stabilized by thebalance of the forces which the coupling receives. For that reason, inthis embodiment, the receiving surfaces 150 e are disposed at thediametrically opposed positions (180 degrees). More particularly, inthis embodiment, the receiving surface 150 e 1 and the receiving surface150 e 3 are diametrically opposed relative to each other, and thereceiving surface 150 e 2 and the surface 150 e 4 are diametricallyopposed relative to each other (FIG. 8 (d)). By this arrangement, theforces which the coupling 150 receives constitute a force couple.Therefore, the coupling 150 can continue rotary motion only by receivingthe force couple. For this reason, the coupling 150 can rotate withoutthe necessity of being specified in the position of the rotation axis L2thereof. In addition, as for the number thereof, as long as the pins 182of the drive shaft 180 (the rotational force applying portion) can enterthe standing-by portions 150 k 1-150 k 2, it is possible to selectsuitably. In this embodiment, as shown in FIG. 8 the four receivingsurfaces are provided. This embodiment is not limited to this example.For example, the receiving surfaces 150 e (projections 150 d 1-150 d 4)do not need to be disposed on the same circumference (the phantom circleC1 and FIG. 8(d)). Or, it is not necessary to dispose at thediametrically opposed positions. However, the effects described abovecan be provided by disposing the receiving surfaces 150 e as describedabove.

Here, in this embodiment, the diameter of the pin is approximately 2 mm,and a circumferential length of the stand-by portion 150 k isapproximately 8 mm. The circumferential length of the stand-by portion150 k is an interval between adjacent projections 150 d (on the phantomcircle). The dimensions are not limiting to the present invention.

Similarly to the opening 150 m, a drum shaft insertion opening portion150 l has a conical rotational force receiving surface 150 i of an as anexpanded part which expands toward the drum shaft 153 in the state whereit is mounted to the cartridge B. The receiving surface 150 iconstitutes a recess 150 q, as shown in FIG. 8 (f).

By this, irrespective of the rotation phase of the photosensitive drum107 in the cartridge B, the coupling 150 can pivot among a rotationalforce transmitting angular position, a pre-engagement angular position,and a disengaging angular position to the drum axix L1 without beingprevented by the free end portion of the drum shaft 153. The recess 150q is constituted in the illustrated example by a conical receivingsurface 150 i which it has centering on the axis L2. The standbyopenings 150 g 1 or 150 g 2 (“opening”) are provided in the receivingsurface 150 i (FIG. 8b ). As for the coupling 150, the pins 155 can beinserted into the inside of this opening 150 g 1 or 150 g 2 so that itmay be mounted to the drum shaft 153. And, the size of the openings 150g 1 or 150 g 2 is larger than the outer diameter of the pin 155. Bydoing so, irrespective of the rotation phase of the photosensitive drum107 in the cartridge B, the coupling 150 is pivotable among therotational force transmitting angular position and the pre-engagementangular position (or disengaging angular position) as will be describedhereinafter without being prevented by the pin 155.

More particularly, the projection 150 d is provided adjacent to the freeend of the recess 150 z. And, the projections (projections) 150 dproject in the intersection direction crossing with the rotationaldirection in which the coupling 150 rotates, and are provided with theintervals along the rotational direction. And, in the state where thecartridge B is mounted to the apparatus main assembly A, the receivingsurfaces 150 e engage to or abutted to the pin 182, and are pushed bythe pin 182.

By this, the receiving surfaces 150 e receive the rotational force fromthe drive shaft 180. In addition, the receiving surfaces 150 e aredisposed in equidistant from the axis L2, and constitute a pairinterposing the axis L2 they are constituted by the surface in theintersection direction in the projections 150 d. In addition, thestanding-by portions (recesses) 150 k are provided along the rotationaldirection, and they are depressed in the direction of the axis L2.

The standing-by portion 150 k is formed as a space between the adjacentprojections 150 d. In the state where the cartridge B is mounted to theapparatus main assembly A, the pin 182 enters the standing-by portion150 k, and it stands by for being driven. And, when the drive shaft 180rotates, the pin 182 pushes the receiving surface 150 e.

By this, the coupling 150 rotates.

The rotational force receiving surface (rotational force receivingmember (portion)) 150 e may be disposed inside of the driving shaftreceiving surface 150 f. Or, the receiving surface 150 e may be providedin the portion outwardly projected from the receiving surface 150 f withrespect to the direction of the axis L2. When the receiving surface 150e is disposed inside of the receiving surface 150 f, the standing-byportion 150 k is disposed inside of the receiving surface 150 f

More particularly, the standing-by portion 150 k is the recess providedbetween the projections 150 d in the inside of the arc part of thereceiving surface 150 f. In addition, when the receiving surface 150 eis disposed at the position which outwardly projects, the standing-byportion 150 k is the recess positioned between the projections 150 d.Here, the recess may be a through hole extended in the direction of theaxis L2, or it may be closed at one end thereof. More particularly, therecess is provided by the space region provided between the projection150 d. And, what is necessary is just to be able to enter the pin 182into the region in the state where the cartridge B is mounted to theapparatus main assembly A.

These structures of the standing-by portion apply similarly to theembodiments as will be described hereinafter.

In FIG. 8 (e), the rotational force transmission surfaces (therotational force transmitting portions) 150 h and (150 h 1 or 150 h 2)are provided in the upstream, with respect to the clockwise direction(X1), of the opening 150 g 1 or 150 g 2. And, the rotational force istransmitted to the photosensitive drum 107 from the coupling 150 by theconvection sections 150 h 1 or 150 h 2 contacting to any of the pins 155a 1, 155 a 2. More particularly, the transmitting surfaces 150 h 1 or150 h 2 push the side surface of the pin 155. By this, the coupling 150rotates with the center thereof aligned with the axis L2. Thetransmitting surface 150 h 1 or 150 h 2 is extended in the directioncrossing with the rotational direction of the coupling 150.

Similarly to the projection 150 d, it is desirable to dispose thetransmitting surfaces 150 h 1 or 150 h 2 diametrically opposed relativeto each other on the same circumference.

At the time of manufacturing the drum coupling member 150 with aninjection molding, the connecting portion 150 c may become thin. This isbecause the coupling is manufactured so that the driving force receivingportion 150 a, the driving portion 150 b and the connecting portion 150c have a substantially uniform thickness. When the rigidity of theconnecting portion 150 c is insufficient, therefore, it is possible tomake the connecting portion 150 c thick so that driven portion 150 a,the driving portion 150 b, and the connecting portion 150 c have thesubstantially equivalent thickness.

(6) Drum Bearing Member

The description will be made, referring to FIG. 9, about a drum bearingmember. FIG. 9 (a) is a perspective view, as seen from a drive shaftside, and FIG. 9 (b) is a perspective view, as seen from thephotosensitive drum side.

The drum bearing member 157 rotatably supports the photosensitive drum107 on the second frame 118. In addition, the bearing member 157 has afunction of positioning the second frame unit 120 in the apparatus mainassembly A. Further, it has the function of retaining the coupling 150so that the rotational force can be transmitted to the photosensitivedrum 107.

As shown in FIG. 9 an engaging portion 157 d positioned to the secondframe 118 and a peripheral part 157 c positioned in the apparatus mainassembly A are substantially co-axially disposed. The engaging portion157 d and the peripheral part 157 c are annular. And, the coupling 150is disposed in the space portion 157 b inside thereof. The engagingportion 157 d and the peripheral part 157 c are provided with a rib 157e for retaining the coupling 150 in the cartridge B in the neighborhoodof the central portion with respect to the axial direction. The bearingmember 157 is provided with holes 157 g 1 or 157 g 2 which penetrate theabutment surface 157 f and the fixing screw for fixing the bearingmember 157 to the second frame 118. As will be described hereinafter,the guide portion 157 a for mounting and demounting on and the cartridgeB relative to the apparatus main assembly A is integrally provided onthe bearing member 157.

(7) Coupling Mounting Method

Referring to FIG. 10-FIG. 16, the description will be made as to themounting method of the coupling. FIG. 10 (a) is an enlarged view, asseen from the driving side surface, of the major part around thephotosensitive drum. FIG. 10 (b) is an enlarged view, as seen from thenon-driving side surface, of the major part. FIG. 10 (c) is a sectionalview taken along S4-S4 of FIG. 10 (a). FIGS. 11 (a) and (b) are anexploded perspective views which illustrate the state before attachmentof the primary members of the second frame unit. FIG. 11 (c) is asectional view taken along S5-S5 in FIG. 11 (a). FIG. 12 is a sectionalview which illustrates a state after attaching. FIG. 13 is a sectionalview taken along S6-S6 of FIG. 11 (a). FIG. 14 is a sectional view whichillustrates a state after rotating the coupling and the photosensitivedrum through 90 degrees from the state of FIG. 13. FIG. 15 is aperspective view which illustrates the combined state of the drum shaftand the coupling. FIG. 15(a 1)-(a 5) are front views, as seen from theaxial direction of the photosensitive drum, and FIG. 15(b 1)-(b 5) areperspective views. FIG. 16 is a perspective view which illustrates thestate where the coupling is inclined in the process cartridge.

As shown in FIG. 15 the coupling 150 is mounted so that the axis L2thereof can incline in any direction relative to the axis L1 of the drumshaft 153 (coaxial with the photosensitive drum 107).

In FIG. 15 (a 1) and FIG. 15 (b 1), the axis L2 of the coupling 150 isco-axial with the axis L1 of the drum shaft 153. The state when thecoupling 150 is inclined upward from this state is illustrated in FIGS.15 (a 2) and (b 2). As shown in this Figure, when the coupling 150 isinclined toward the opening 150 g side, the opening 150 g moves alongthe pin 155. As a result, the coupling 150 is inclined about an axis AXperpendicular to the axis of the pin 155.

In FIGS. 15 (a 3) and (b 3), the state where the coupling 150 isinclined rightward is shown. As shown in this Figure, when the coupling150 inclines in the orthogonality direction of the opening 150 g, theopening 150 g rotates about the pin 155. The axis of rotation is theaxis line AY of the pin 155.

The state where the coupling 150 is inclined downward is shown in FIGS.15 (a 4) and (b 4), and the state where the coupling 150 is inclinedleftward is shown in FIGS. 15 (a 5) and (b 5). The rotation axes AX andAY have been described in the foregoing.

In the directions different from the inclining direction described inthe foregoing, for example, in the 45-degree direction in FIG. 15 (a 1)and so on, the inclination is made by combining the rotations in theaxes AX and the directions of AY. Thus, the axis L2 can be pivoted inany direction relative to the axis L1.

More particularly, the transmitting surface (rotational forcetransmitting portion) 150 h is movable relative to the pin (rotationalforce receiving portion) 155. The pin 155 has the transmitting surface150 in the movable condition. And, the transmitting surface 150 h andthe pin 155 are engaged to each other in the rotational direction of thecoupling 150. In this manner, the coupling 150 is mounted to thecartridge. In order to accomplish this, the gap is provided between thetransmitting surface 150 h and the pin 155. By this, the coupling 150 ispivotable in all directions substantially relative to the axis L1.

As described above, the opening 150 g is extended in the direction (therotational axis direction of the coupling 150) crossing with theprojection direction of the pins 155 at least. Therefore, as has beendescribed hereinbefore, the coupling 150 is pivotable in all thedirections. It has been mentioned that the axis L2 is slantable orinclinable in any direction relative to the axis L1. However, the axisL2 does not necessarily need to be linearly slantable to thepredetermined angle in the full range of 360-degree direction in thecoupling 150. For example, the opening 150 g can be selected to beslightly wider in the circumferential direction. By doing so, the timeof the axis L2 inclining relative to the axis L1, even if it is the casewhere it cannot incline to the predetermined angle linearly, thecoupling 150 can rotate to a slight degree around the axis L2.Therefore, it can be inclined to the predetermined angle. In otherwords, the amount of the play in the rotational direction of the opening150 g is selected properly if necessary.

In this manner, the coupling 150 is revolvable or swingable over thefull-circumference substantially relative to drum shaft (rotationalforce receiving member) 153. More particularly, the coupling 150 ispivotable over the full-circumference thereof substantially relative tothe drum shaft 153.

Furthermore, as will be understood from the foregoing explanation, thecoupling 150 is capable of whirling in and substantially over thecircumferential direction of the drum shaft 153. Here, the whirlingmotion is not a motion with which the coupling itself rotates about theaxis L2, but the inclined axis L2 rotates about the axis L1 of thephotosensitive drum, although the whirling here does not preclude therotation of the coupling per se about the axis L2 of the coupling 150.

The process of the assemblying the parts will be described.

First, the photosensitive drum 107 is mounted in the direction X1 inFIG. 11 (a) and FIG. 11 (b). At this time, the bearing portion 151 d ofthe flange 151 is made to substantially co-axially engage with thecentering portion 118 h of the second frame 118. In addition, bearinghole 152 a (FIG. 7 of the flange 152 (a)) is substantially co-axiallyengaged with the centering portion 118 g of the second frame 118.

The drum grounding shaft 154 is inserted into the direction X2. And, thecentering portion 154 b is penetrated through the bearing hole 152 a(FIG. 6b ) and the centering hole 118 g (FIG. 10 (b)). At this time, thecentering portion 154 b and the bearing hole 152 a are supported so thatthe photosensitive drum 107 is rotatable. On the other hand, thecentering portion 154 b and the centering hole 118 g are supportedfixedly by the press-fitting and so on. By this, the photosensitive drum107 is rotatably supported relative to the second frame. Alternatively,it may be fixed non-rotatably relative to the flange 152, and the drumgrounding shaft 154 (centering portion 154 b) may be rotatably mountedto the second frame 118.

The coupling 150 and the bearing member 157 are inserted in thedirection X3. First, the driving portion 150 b is inserted toward thedirection X3 downstream, while maintaining the axis L2 (FIG. 11c ) inparallel with X3. At this time, the phase of the pin 155 and the phaseof the opening 150 g are matched with each other, and the pin 155 ismade inserted into the openings 150 g 1 or 150 g 2. And, the free endportion 153 b of the drum shaft 153 is abutted to the drum bearingsurface 150 i. The free end portion 153 b is the spherical surface andthe drum bearing surface 150 i is a conic surface. That is, the drumbearing surface 150 i of the conic surface which is the recess, and thefree end portion 153 b of the drum shaft 153 which is the projectioncontact to each other. Therefore, the driving portion 150 b side ispositioned relative to the free end portion 153 b. As has been describedhereinbefore, when the coupling 150 rotates by the transmission of therotational force from the apparatus main assembly A, the pin 155positioned in the opening 150 g will be pushed by the rotational forcetransmission surfaces (the rotational force transmitting portions) 150 h1 or 150 h 2 and (FIG. 8b ). By this, the rotational force istransmitted to the photosensitive drum 107. Thereafter, the engagingportion 157 d is inserted downstream with respect to the direction X3.By this, a part of coupling 150 is received in the space portion 157 b.And, the engaging portion 157 d supports the bearing portion 151 d ofthe flange 151, so that the photosensitive drum 107 is rotatable. Inaddition, the engaging portion 157 d engages with the centering portion118 h of the second frame 118. The abutment surface 157 f of the bearingmember 157 abuts to the abutment surface 118 j of the second frame 118.And, the screws 158 a, 158 b are penetrated through the holes 157 g 1 or157 g 2, and they are fixed to the screw holes 118 k 1, 118 k 2 of thesecond frame 118, so that the bearing member 157 is fixed to the secondframe 118 (FIG. 12).

The dimensions of the various portions of the coupling 150 will bedescribed. As shown in FIG. 11 (c), a maximum outer diameter of thedriven portion 150 a is ΦD2, a maximum outer diameter of the drivingportion 150 b is ΦD1, and a small diameter of the standby opening 150 gis ΦD3. In addition, a maximum outer diameter of the pin 155 is ΦD5, andan inner diameter of the retention rib 157 e of the bearing member 157is ΦD4. Here, the maximum outer diameter is the outer diameter of amaximum rotation locus about the axis L1 or the axis L2. At this time,since ΦD5<ΦD3 is satisfied, the coupling 150 can be assembled to thepredetermined position by the straight mounting operation in thedirection X3 therefore, the assembling property is high (the state afterthe assembly is shown in FIG. 12). The diameter of the inner surface ΦD4of the retention rib 157 e of the bearing member 157 is larger than ΦD2of the coupling 150, and smaller than ΦD1 (ΦD2<ΦD4<ΦD1). By this, justthe step attached to the direction X3 straight is sufficient to assemblethe bearing member 157 to the predetermined position. For this reason,the assembling property can be improved (the state after the assembly isshown in FIG. 12).

As shown in FIG. 12, the retention rib 157 e of the bearing member 157is disposed closely to a flange portion 150 j of the coupling 150 in thedirection of the axis L1. More specifically, in the direction of theaxis L1, the distance from an end surface 150 j 1 of the flange portion150 j to the axis L4 of the pin 155 is n1. In addition, the distancefrom an end surface 157 e 1 of the rib 157 e to the other end surface157 j 2 of the flange portion 150 j is n2. The distance n2<distance n1is satisfied.

In addition, with respect to the direction perpendicular to the axis L1,the flange portion 150 j and the rib 157 e are disposed so that they areoverlapped relative to each other. More specifically, the distance n4from the inner surface 157 e 3 of the rib 157 e to the outer surface 150j 3 of the flange portion 150 j is the overlap amount n4 with respect tothe orthogonality direction of the axis L1.

By such settings, the pin 155 is prevented from disengaging from theopening 150 g. That is, the movement of the coupling 150 is limited bythe bearing member 157. Thus, the coupling 150 does not disengage fromthe cartridge. The prevention of disengagement can be accomplishedwithout additional parts. The dimensions described above are desirablefrom the standpoint of reduction of manufacturing and assemblying costs.However, the present invention is not limited to these dimensions.

As described above (FIG. 10 (c) and FIG. 13), the receiving surface 150i which is the recess 150 q of the coupling 150 is in contact with thefree end surface 153 b of the drum shaft 153 which is the projection.Therefore, the coupling 150 is swung along the free end portion (thespherical surface) 153 b about the center P2 of the free end portion(the spherical surface) 153 b in other words, the axis L2 is pivotablesubstantially in all directions irrespective of the phase of the drumshaft 153. The axis L2 of the coupling 150 is pivotable in alldirections substantially. As will be described hereinafter, in orderthat the coupling 150 may engage with the drive shaft 180, the axis L2is inclined toward the downstream with respect to the mounting directionof the cartridge B relative to the axis L1, just before the engagement.In other words, as shown in FIG. 16, the axis L2 inclines so that thedriven portion 150 a positions at the downstream side with respect tothe mounting direction X4 relative to the axis L1 of the photosensitivedrum 107 (the drum shaft 153). In FIGS. 16 (a)-(c), although thepositions of the driven portion 150 a slightly differ relative to eachother, they are positioned at the downstream side with respect to themounting direction X4 in any case.

The still more detailed description will be made.

As shown in FIG. 12, a distance n3 between a maximum outer diameter partand bearing member 157 of the driving portion 150 b is selected so thata slight gap is provided between them. By this, as has been describedhereinbefore, the coupling 150 is pivotable.

As shown in FIG. 9, the rib 157 e is a semi-circular rib. The rib 157 eis disposed at the downstream with respect to the mounting direction X4of the cartridge B. Therefore, as shown in FIG. 10 (c), the drivenportion 150 a side of the axis L2 is greatly pivotable in the directionX4. In other words, the driving portion 150 b side of the axis L2 isgreatly pivotable in the direction of angle α3) at phase (FIG. 9(a) atwhich the rib 157 e is not disposed. FIG. 10 (c) illustrates the statewhere the axis L2 inclined. In addition, it can also be pivoted to thestate substantially parallel to the axis L1 by which it is shown in FIG.13 from the state of the inclined axis L2 shown in FIG. 10 (c). In thismanner, the rib 157 e is disposed. By this, the coupling 150 can bemounted by the simple method to the cartridge B. Further, in addition,no matter the drum shaft 153 may stop with what phase, the axis L2 ispivotable relative to the axis L1. The rib is not limited to thesemi-circular rib. As long as the coupling 150 is pivotable to thepredetermined direction, and it is possible to mount the coupling 150 toCartridge B (photosensitive drum 107), any rib is usable. In thismanner, the rib 157 e has a function as the regulating means forregulating the inclining direction of the coupling 150.

In addition, a distance n2 (FIG. 12) in the direction of the axis L1from the rib 157 e to the flange portion 150 j is shorter than adistance n1 from the center of the pin 155 to the driving portion 150 bside edge. By this, the pin 155 does not disengage from the opening 150g.

As described above, the coupling 150 is supported by the both of thedrum shaft 153 and the drum bearing 157 substantially. Moreparticularly, the coupling 150 is mounted to the cartridge B by the drumshaft 153 and the drum bearing 157 substantially.

The coupling 150 has a play (the distance n2) in the direction of theaxis L1 relative to the drum shaft 153. Therefore, the receiving surface150 i (the conic surface) may not contact snuggly the drum shaft freeend portion 153 b (the spherical surface). In other words, the center ofthe pivoting may deviate from the center of curvature P2 of thespherical surface. However, even in such a case, the axis L2 ispivotable relative to the axis L1. For this reason, the purpose of thisembodiment can be accomplished.

In addition, maximum possible inclination angle α4 (FIG. 10 (c)) betweenthe axis L1 and the axis L2 is the one half of the taper angle (α1, FIG.8(f)) between the axis L2 and the receiving surface 150 i. The receivingsurface 150 i has conical shape and the drum shaft 153 has thecylindrical shape. For this reason, the gap g of angle α1/2 is providedbetween them. By this, the taper angle α1 changes, and therefore, theinclination angle α4 of the coupling 150 are set to the optimal value.In this manner, since the receiving surface 150 i is the conic surface,the circular column portion 153 a of the drum shaft 153 is satisfactorywith the simple cylindrical shape. In other words, the drum shaft doesnot need to have a complicated configuration. Therefore, the machiningcost of the drum shaft can be suppressed.

In addition, as shown in FIG. 10 (c), when the coupling 150 inclines, apart of coupling can circumvent into illustration) by space portion 151e (hatching of the flange 151. By this, the lightening cavity (Spaceportion 151 e) of the gear portion 151 c can be used without futility.Therefore, effective use of the space can be done. Incidentally, thelightening cavity (Space portion 151 e) is not usually used.

As described above, in the embodiment of FIG. 10 (c), the coupling 150is mounted so that a part of a coupling 150 may locate at the positionwhich overlaps the gear portion 151 c with respect to the direction ofthe axis L2. In the case of the flange which does not have the gearportion 151 c, a part of coupling 150 can further enter into thecylinder 107 a.

When the axis L2 inclines, the width of the opening 150 g is selected inconsideration of the size of the pin 155 so that the pin 155 may notinterfere.

More particularly, the transmitting surface (rotational forcetransmitting portion) 150 h is movable relative to the pin (rotationalforce receiving portion) 155. The pin 155 has the transmitting surface150 in the movable condition. And, the transmitting surface 150 h andthe pin 155 are engaged to each other in the rotational direction of thecoupling 150. In this manner, the coupling 150 is mounted to thecartridge. In order to accomplish this, the gap is provided between thetransmitting surface 150 h and the pin 155. By this, the coupling 150 ispivotable in all directions substantially relative to the axis L1.

The locus of the flange portion 150 j when the driven portion 150 a sideinclines in the direction X5 is illustrated by the region T1 in FIG. 14.As shown in the Figure, even if the coupling 150 inclines, theinterference with the pin 155 does not occur, and therefore, the flangeportion 150 j can be provided over the full-circumference of thecoupling 150 (FIG. 8 (b)). In other words, the shaft receiving surface150 i has conical shape, and therefore, when the coupling 150 inclines,the pin 155 does not enter in the region T1. For this reason, thecutting away range of the coupling 150 is minimized. Therefore, therigidity of the coupling 150 can be assured.

In the above described mounting process, the process (the non-drivingside) in the direction X2 and the process (the driving side) in thedirection X3 may be exchanged.

The bearing member 157 has been described as being fixed on the screwsto the second frame 118. However, the present invention is not limitedto such an example. For example, like the bonding, if the bearing member157 is fixable to the second frame 118, the any method will be usable.

(8) Drive Shaft and Driving Structure of the Apparatus Main Assembly

Referring to FIG. 17, the description will be made as to the structurefor driving the photosensitive drum 107 in the apparatus main assemblyA. FIG. 17 (a) is a partly broken perspective view of the side plate ofthe driving side in the state where the cartridge B is not mounted tothe apparatus main assembly A. FIG. 17 (b) is a perspective view whichillustrates only the drum driving structure. FIG. 17 (c) is thesectional view taken along S7-S7 of FIG. 17 (b).

The drive shaft 180 has the substantially similar structure as the abovedescribed drum shaft 153. In other words, the free end portion 180 bthereof forms a semispherical surface. In addition, it has a rotationalforce transmitting pin 182 as a rotational force applying portion of themain part 180 a of the cylindrical shape which penetrates the centersubstantially. The rotational force is transmitted to the coupling 150by this pin 182.

A drum driving gear 181 substantially co-axial with the axis of thedrive shaft 180 is provided on the longitudinally opposite side of thefree end portion 180 b of the drive shaft 180. The gear 181 is fixednon-rotatably relative to the drive shaft 180. Therefore, the rotationof the gear 181 will also rotate the drive shaft 180.

In addition, the gear 181 is engaged with a pinion gear 187 forreceiving the rotational force from the motor 186. Therefore, therotation of the motor 186 will rotate the drive shaft 180 through thegear 181.

In addition, the gear 181 is rotatably mounted to the apparatus mainassembly A by the bearing members 183, 184. At this time, the gear 181does not move relative to the direction of the axial direction L3 of thedrive shaft 180 (the gear 181), that is, it is positioned with respectto the axial direction L3. Therefore, the gears 181 and the bearingmembers 183 and 184 can be closely disposed relative to each other withrespect to the axial direction. In addition, the drive shaft 180 doesnot move with respect to the direction thereof of the axis L3.Therefore, the drive shaft 180 and the gap between the bearing members183 and 184 have the sizes which permit the rotation of the drive shaft180. For this reason, the position of the gear 181 with respect to thediametrical direction relative to the gear 187 is determined correctly.

In addition, although it has been described that the drive is directlytransmitted to the gear 181 from the gear 187, the present invention isnot limited to such an example. For example, it is the satisfactoryusing a plurality of gears on account of the motor disposed at theapparatus main assembly A. Alternatively, it is possible to transmit therotational force by a belt and so on.

(9) Main Assembly Side Mounting Guide for Guiding Cartridge B

As shown in FIGS. 18 and 19, the mounting means 130 of this embodimentincludes main assembly guides 130R1, 130R2, 130L1, 130L2 provided in theapparatus main assembly A.

They are provided opposed to the both side surfaces of the cartridgemounting space (the cartridge set portion 130 a) provided in theapparatus main assembly A (the driving side surface in FIG. 18) (theside surface in FIG. 19 in which it does not drive). The main assemblyguides 130R1, 130R2 are provided in the main assembly opposed to thedriving side of the cartridge B, and they are extended along themounting direction of the cartridge B. On the other hand, the mainassembly guides 130L1, 130L2 are provided in the main assembly sideopposed to the non-driving side of the cartridge B, and they areextended along the mounting direction of the cartridge B. The mainassembly guides 130R1, 130R2 and the main assembly guides 130L1, 130L2are opposed to each other. At the time of mounting the cartridge B tothe apparatus main assembly A these guides 130R1, 130R2, 130L1, 130L2guide the cartridge guides as will be described hereinafter. At the timeof mounting the cartridge B to the apparatus main assembly A, thecartridge door 109 which can be opened and closed relative to theapparatus main assembly A about a shaft 109 a is opened. And, themounting, into the apparatus main assembly A, of the cartridge B iscompleted by closing the door 109. At the time of taking out thecartridge B from the apparatus main assembly A, the door 109 is opened.These operations are effected by the user.

(10) Positioning Portion, Relative to Mounting Guide and Apparatus MainAssembly A for Cartridge B

As shown in FIGS. 2 and 3, in this embodiment, the outer periphery 157 aof the outside end of the bearing member 157 functions also as acartridge guide 140R1. In addition, the outer periphery 154 a of theoutside end of the drum grounding shaft 154 functions also as acartridge guide 140L1.

In addition, the one longitudinal end (the driving side) of the secondframe unit 120 is provided with the cartridge guide 140R2 on the upperportion of the cartridge guide 140R1. And, the other end (thenon-driving side) in the longitudinal direction is provided with thecartridge guide 140L2 on the upper portion of the cartridge guide 140L1.

More particularly, the one longitudinal end of the photosensitive drum107 is provided with the cartridge side guides 140R1, 140R2 outwardlyprojected from the cartridge frame B1. In addition, the other end in thelongitudinal direction is provided with the cartridge side guides 140L1,140L2 outwardly projected from the cartridge frame B1. The guides 140R1,140R2, 140L1, 140L2 is projected toward the along said longitudinaldirection here and there outside. More particularly, the guides 140R1,140R2, 140L1, 140L2 are projected from the cartridge frame B1 along theaxis L1. And, at the time of mounting the cartridge B to the apparatusmain assembly A, and at the time of demounting the cartridge B from theapparatus main assembly A the guide 140R1 is guided by the guide 130R1,and the guide 140R2 is guided by the guide 130R2. In addition, at thetime of mounting the cartridge B to the apparatus main assembly A and atthe time of demounting the cartridge B from the apparatus main assemblyA the guide 140L1 is guided by the guide 130L1, and the guide 140L2 isguided by the guide 130L2. In this manner, the cartridge B is mounted tothe apparatus main assembly A, moving in the direction substantiallyperpendicular to the axial direction L3 of the drive shaft 180, and itis similarly demounted from the apparatus main assembly A. In addition,in this embodiment, the cartridge guides 140R1, 140R2 are moldedintegrally with the second frame 118. However, separate members areusable as the cartridge guides 140R1, 140R2.

(11) Mounting Operation of Process Cartridge

Referring to FIG. 20, the mounting operation, into the apparatus mainassembly A, of the cartridge B will be described. FIG. 20 shows themounting process. FIG. 20 is a sectional view taken along S9-S9 of FIG.18.

As shown in FIG. 20 (a), the door 109 is opened by the user. And, thecartridge B is dismountably mounted relative to the cartridge mountingmeans 130 (the installation section 130 a) provided in the apparatusmain assembly A.

At the time of mounting the cartridge B to the apparatus main assemblyA, in the driving side, the cartridge guides 140R1, 140R2 are insertedalong the main assembly guides 130R1, 130R2, as shown in FIG. 20 (b). Inaddition, also about the non-driving side, the cartridge guides 140L1,140L2 (FIG. 3) are inserted along the main assembly guides 130L1, 130L2(FIG. 19).

When the cartridge B is further inserted in the direction of the arrowX4, the coupling between the drive shaft 180 and the cartridge B isestablished and then, the cartridge B is mounted to the predeterminedposition (the installation section 130 a) (the provision). In otherwords, as shown in FIG. 20 (c), the cartridge guide 140R1 contacts tothe positioning portion 130R1 a of the main assembly guide 130R1, andthe cartridge guide 140R2 contacts to the positioning portion 130R2 a ofthe main assembly guide 130R2. In addition, the cartridge guide 140L1contacts to the positioning portion 130L1 a (FIG. 19) of the mainassembly guide 130L1, and the cartridge guide 140L2 contacts to thepositioning portion 130L2 a of the main assembly guide 130L2 since thisstate is substantially symmetrical, the illustration is not made. Inthis manner, the cartridge B is dismountably mounted to the installationsection 130 a by the mounting means 130. More particularly, thecartridge B is mounted in the state positioned in the apparatus mainassembly A. And, in the state where the cartridge B is mounted to theinstallation section 130 a, the drive shaft 180 and the coupling 150 arein the engaged state relative to each other.

More particularly, the coupling 150 is in a rotational forcetransmitting angular position as will be described hereinafter.

The image forming operation is enabled by the cartridge B being mountedto the set portion 130 a.

When the cartridge B is provided at the predetermined position, apressing receptor portion 140R1 b (FIG. 2) of the cartridge B receivesthe urging force from an urging spring 188R (FIG. 18, FIG. 19, and FIG.20). In addition, from an urging spring 188L, a pressing receptorportion 140L1 b (FIG. 3) of the cartridge B receives the urging force.By this, the cartridge B (photosensitive drum 107) is correctlypositioned relative to the transfer roller, the optical means, and so onof the apparatus main assembly A.

The user may enter the cartridge B to the set portion 130 a as describedabove. Alternatively, the user enters the cartridge B to the positionhalfway, and the last mounting operation may be effected by anothermeans. For example, utilizing the operation which shuts the door 109, apart of door 109 acts on the cartridge B which is in the position in thecourse of the mounting to push the cartridge B into the final mountedposition. Further alternatively, the user pushes, into the cartridge Bto the middle, the cartridge B, and lets it fall into the set portion130 a by the weight, after that.

Here, as shown in FIG. 18-20, the mounting and demounting of thecartridge B relative to the apparatus main assembly A is effected by themovement in the direction substantially perpendicular to the directionof the axis L3 of the drive shaft 180 (FIG. 21) corresponding to theseoperations, the position between the drive shaft 180 and the coupling150 change between the engaged state and the disengagement state.

Here, the description will be made about “perpendicular substantially”.

Between the cartridge B and the apparatus main assembly A, in order tomount and demount the cartridge B smoothly, small gaps are provided.More specifically, the small gaps are provided between the guide 140R1and the guide 130R1 with respect to the longitudinal direction, betweenthe guide 140R2 and the guide 130R2 with respect to the longitudinaldirection, between the guide 140L1 and the guide 130L1 with respect tothe longitudinal direction, and between the guide 140L2 and the guide130L2 with respect to the longitudinal direction. Therefore, at the timeof the mounting and demounting of the cartridge B relative to theapparatus main assembly A, the whole cartridge B can slightly inclinewithin the limits of the gaps. For this reason, the perpendicularity isnot meant strictly. However, even in such a case, the present inventionis accomplished with the effects thereof. Therefore, the term“perpendicular substantially” covers the case where the cartridgeslightly inclines.

(12) Coupling Engaging Operations and Drive Transmission

As stated in the foregoing, immediately before or substantiallysimultaneously with positioning in a predetermined position of theapparatus main assembly A, the coupling 150 is engaged with the driveshaft 180. More particularly, the coupling 150 positions at therotational force transmitting angular position. Here, the predeterminedposition is the set portion 130 a. Referring to FIGS. 21, 22, and 23,the description will be made with respect to the engaging operation ofthis coupling. FIG. 21 is a perspective view which illustrates the majorpart of the drive shaft and the driving side of the cartridge. FIG. 22is a longitudinal sectional view, as seen from the lower part of theapparatus main assembly. FIG. 23 is a longitudinal sectional view, asseen from the lower part of the apparatus main assembly. Here, theengagement means the state in which the axis L2 and the axis L3 aresubstantially co-axial relative to each other, and the drivetransmission is possible.

As shown in FIG. 22, the cartridge B is mounted to the apparatus mainassembly A in the direction (arrow X4) substantially perpendicular tothe axis L3 of the drive shaft 180. Or, it is demounted from theapparatus main assembly A. In the pre-engagement angular position, theaxis L2 (FIG. 22 a) of the coupling 150 inclines toward downstream withrespect to the mounting direction X4 beforehand relative to the axis L1(FIG. 22(a) of the drum shaft 153 (FIG. 21 a and FIG. 22(a).

In order to incline the coupling toward the pre-engagement angularposition beforehand, the structure of the embodiment 3-embodiment 9 aswill be described hereinafter is used, for example.

Because of the inclination of the coupling 150, the downstream free end150A1 with respect to the mounting direction X4 is closer to thephotosensitive drum 107 than the drive shaft free end 180 b 3 in thedirection of the axis L1. In addition, the upstream free end 150A2 withrespect to the mounting direction is closer to the pin 182 than thedrive shaft free end 180 b 3 (FIG. 22(a), (b)). Here, the free endposition is the position nearest to the drive shaft of the drivenportion 150 a shown in FIGS. 8(a) and (c) with respect to the directionof the axis L2, and it is the remotest position from the axis L2. Inother words, it is an edge line of the driven portion 150 a of thecoupling 150, or an edge line of the projection 150 d depending on therotation phase of the coupling 150 (150A) in FIGS. 8(a) and (c).

The free end position 150A1 of the coupling 150 passes by the driveshaft free end 180 b 3. And, after the coupling 150 carries out bypassage of the drive shaft free end 180 b 3, the receiving surface(cartridge side contact portion) 150 f or the projection (cartridge sidecontact portion) 150 d contacts with the free end portion 180 b of driveshaft (main assembly side engaging portion) 180, or pin (main assemblyside engaging portion) (rotational force applying portion) 182. And,corresponding to the mounting operation of the cartridge (B), the axisL2 is inclined so that it may align substantially with the axis L1 (FIG.22 (c)). And, when the coupling 150 inclines from said pre-engagementangular position and the axis L2 thereof aligns substantially with theaxis L1, the rotational force transmitting angular position is reached.And, finally, the position of the cartridge (B) is determined relativeto the apparatus main assembly (A). Here, the drive shaft 180 and thedrum shaft 153 are substantially co-axial relative to each other. Inaddition, the receiving surface 150 f opposes to the spherical free endportion 180 b of the drive shaft 180. This state is the engaged statebetween the coupling 150 and the drive shaft 180 (FIG. 21 (b) and FIG.22 (d)). At this time, the pin 155 (unshown) is positioned in theopening 150 g (FIG. 8 (b)). In other words, the pin 182 takes thestanding-by portion 150 k. Here, the coupling 150 covers the free endportion 180 b.

The receiving surface 150 f constitutes the recess 150 z. And, therecess 150 z has the conical shape.

As has been described above, the coupling 150 is pivotable relative tothe axis L1. And, corresponding to the movement of the cartridge (B), apart of coupling 150 (the receiving surface 150 f and/or 150 d ofprojections) which is the cartridge side contact portion contacts to themain assembly side engaging portion (the drive shaft 180 and/or the pin182). By this, the pivoting motion of the coupling 150 is effected. Asshown in FIG. 22, the coupling 150 is mounted with the state ofoverlapping, with respect to the direction of the axis L1, with thedrive shaft 180. However, the coupling 150 and the drive shaft 180 areengageable relative to each other with the overlapping state by thepivoting motion of the couplings, as described above.

The mounting operation of the coupling 150 described above can beperformed regardless of the phases of the drive shaft 180 and thecoupling 150. Referring to FIG. 15 and FIG. 23, the detailed descriptionwill be made. FIG. 23 illustrates the phase relation between thecoupling and the drive shaft. In FIG. 23 (a), in a downstream positionwith respect to the mounting direction X4 of the cartridge, the pin 182and the receiving surface 150 f face to each other. In FIG. 23 (b), thepin 182 and the projection 150 d face to each other. In FIG. 23 (c), thefree end portion 180 b and the projection 150 d face to each other. InFIG. 23 (d), the free end portion 180 b and the receiving surface 150 fface to each other.

As shown in FIG. 15, the coupling 150 is pivotably mounted in anydirection relative to the drum shaft 153. More particularly, thecoupling 150 is revolvable. Therefore, as shown in FIG. 23, it canincline toward the mounting direction X4 irrespective of the phase ofthe drum shaft 153 relative to the mounting direction X4 of thecartridge (B). In addition, the inclination angle of the coupling 150 isset, so that regardless of the phases of the drive shaft 180 and thecoupling 150, the free end position 150A1 is made closer to thephotosensitive drum 107 than the axial free end 180 b 3 with respect tothe direction of the axis L1. In addition, the inclination angle of thecoupling 150 is set, so that the free end position 150A2 is made closerto the pin 182 than the axial free end 180 b 3. With such a setting,corresponding to the mounting operation of the cartridge (B), the freeend position 150A1 is passed by the axial free end 180 b 3 in themounting direction X4. And, in the case of FIG. 23 (a), the receivingsurface 150 f contacts the pin 182. In the case of FIG. 23 (b), theprojection (the engaging portion) 150 d contacts the pin (rotationalforce applying portion) 182. In the case of FIG. 23 (c), the projection150 d contacts to the free end portion 180 b. In the case of FIG. 23(d), the receiving surface 150 f contacts to the free end portion 180 b.In addition, by the contact force generated at the time of mounting thecartridge (B), the axis L2 of the coupling 150 moves so that itsubstantially becomes co-axial with the axis L1. By this, the coupling150 is engaged with the drive shaft 180. More particularly, the couplingrecess 150 z covers the free end portion 180 b. For this reason, thecoupling 150 can be engaged with the drive shaft 180 (the pin 182)irrespective of the phases of the drive shaft 180, the coupling 150 andthe drum shaft 153.

In addition, as shown in FIG. 22, the gap is provided between the drumshaft 153 and the coupling 150, so that the coupling is swingable(revolvable, pivotable).

In this embodiment, the coupling 150 moves in a plane of the sheet ofthe drawing of FIG. 22. However, the coupling 150 of this embodiment iscapable of whirling, as described above. Therefore, the motion of thecoupling 150 may include motion not included in the plane of the sheetof the drawing of FIG. 22. In such a case, the change from the state ofFIG. 22(a) to the state of FIG. 22(d) occurs. This applies to theembodiments which will be described hereinafter unless otherwise stated.

Referring to FIG. 24, the rotational force transmitting operation at thetime of rotating the photosensitive drum 107 will be described. Thedrive shaft 180 rotates with the gear 181 in the direction (Figure, X8)by the rotational force received from the driving source (the motor186). And, the pin 182 integral with the drive shaft 180 (182 a 1, 182 a2) contacts to any of the rotational force receiving surfaces(rotational force receiving portion) 150 e 1-150 e 4. More particularly,the pin 182 a 1 contacts any one of the rotational force receivingsurfaces 150 e 1-150 e 4. In addition, the pin 182 a 2 contacts with anyof the rotational force receiving surfaces 150 e 1-150 e 4. By this, therotational force of the drive shaft 180 is transmitted to the coupling150 to rotate the coupling 150. Furthermore, by the rotation of thecoupling 150, the rotational force transmission surfaces (the rotationalforce transmitting portion) 150 h 1 or 150 h 2 of the coupling 150contact to the pin 155 integral with the drum shaft 153. By this, therotational force of the drive shaft 180 is transmitted to thephotosensitive drum 107 through the coupling 150, the rotational forcetransmission surface 150 h 1 or 150 h 2, the pin 155, the drum shaft153, and the drum flange 151. In this manner, the photosensitive drum107 is rotated.

In the rotational force transmitting angular position, the free endportion 153 b is contacted with the receiving surface 150 i. And, thefree end portion (the positioning portion) 180 b of the drive shaft 180is contacted with the receiving surface (the positioning portion) 150 f.By this, the coupling 150 is positioned relative to the drive shaft 180in the state where it is over the drive shaft 180 (FIG. 22(d)).

Here, in this embodiment, even if the axis L3 and the axis L1 deviatefrom the co-axial relations somewhat, the coupling 150 can effect thetransmission of the rotational force because the coupling 150 inclinesslightly. Even if it is such a case, the coupling 150 can rotate withoutcovering the large additional load over the drum shaft 153 and the driveshaft 180. Therefore, the high precision position arrangement operationof the drive shaft 180 and the drum shaft 153 at the time of theassembling is easy. For this reason, the assembling operativity can beimproved.

This is also one of the effects of this embodiment.

In addition, in FIG. 17, as has been described, the position of thedrive shaft 180 and the gear 181 is positioned with respect to thediametrical direction and the axial direction in the predeterminedposition (Set portion 130 a) of the apparatus main assembly (A). Inaddition, the cartridge (B) is positioned in the predetermined positionof the apparatus main assembly as described above. And, the drive shaft180 positioned in said predetermined position and the cartridge (B)positioned in said predetermined position are coupled by the coupling150. The coupling 150 is swingable (pivotable) relative to thephotosensitive drum 107. For this reason, as described above, thecoupling 150 can transmit the rotational force smoothly between thedrive shaft 180 positioned in the predetermined position and thecartridge (B) positioned in the predetermined position. In other words,even if there is some axial deviation between the drive shaft 180 andthe photosensitive drum 107, the coupling 150 can transmit therotational force smoothly.

This is also one of the effects of this embodiment.

In addition, as described above, the cartridge (B) is positioned in thepredetermined position. For this reason, the photosensitive drum 107which is the constituent-element of the cartridge (B) is correctlypositioned relative to the apparatus main assembly (A). Therefore, thespatial relationship between the photosensitive drum 107, and theoptical means 101, the transfer roller 104 or recording material 102 canbe maintained with high precision. In other words, those positiondeviations can be reduced.

The coupling 150 contacts to the drive shaft 180. By this, although ithas been mentioned that the coupling 150 swings from the pre-engagementangular position to the rotational force transmitting angular position,the present invention is not limited to such an example. For example, itis possible to provide the abutting portion as the main assembly sideengaging portion in the position other than the drive shaft of theapparatus main assembly. And, in the mounting process of the cartridge(B), after the free end position 150A1 passes by the drive shaft freeend 180 b 3, a part of coupling 150 (cartridge side contact portion)contacts with this abutting portion. By this, the coupling can receivethe force of the shaking direction (pivoting direction), and it can alsobe made to swing so that the axis L2 becomes substantially co-axial withthe axis L3 (the pivoting). In other words, another means is sufficient,if the axis L1 can substantially co-axially position with the axis L3 ininterrelation with the mounting operation of the cartridge (B).

(13) The Disengaging Operation of the Coupling, and the RemovingOperation of the Cartridge

Referring to FIG. 25, the operation for disengaging the coupling 150from the drive shaft 180 will be described at the time of taking out thecartridge (B) from the apparatus main assembly (A). FIG. 25 is thelongitudinal sectional view, as seen from the apparatus main assemblylower.

First, the position of the pin 182 at the time of demounting thecartridge (B) will be described. After the image formation finishes, aswill be apparent from the foregoing description, the pin 182 ispositioned at any 2 of the standing-by portions 150 k 1-150 k 4 (FIG.8). And, the pin 155 is positioned in the opening 150 g 1 or 150 g 2.

The description will be made with respect to the operation fordisengaging the coupling 150 from the drive shaft 180 in interrelationwith the operation for taking out the cartridge (B).

As shown in FIG. 25, the cartridge (B) is drawn out in the direction(the direction of the arrow X6) substantially perpendicular to the axisL3, at the time of demounting from the apparatus main assembly (A).

In the state where the drive for the drum shaft 153 has stopped, theaxis L2 is substantially co-axial relative to the axis L1 in thecoupling 150 (rotational force transmitting angular position) (FIG. 25(a)). And, the drum shaft 153 moves in the dismounting direction X6 withthe cartridge (B), and the receiving surface 150 f or the projection 150d in the upstream of the coupling 150 with respect to the dismountingdirection contacts at least to the free end portion 180 b of the driveshaft 180(FIG. 25 (a)). And, the axis L2 begins to incline toward theupstream with respect to the dismounting direction X6 (FIG. 25 (b)).This direction is the same as that of the inclination of the coupling150 at the time of the mounting of the cartridge (B) (the pre-engagementangular position). It moves, while the upstream free end portion 150 A3with respect to the dismounting direction X6 contacts to the free endportion 180 b by the dismounting operation from the apparatus mainassembly (A) of this cartridge (B). In more detail, corresponding to themovement to the dismounting direction of the cartridge (B), while a partof coupling 150 (the receiving surface 150 f and/or 150 d ofprojections) which is the cartridge side contact portion contacts withthe main assembly side engaging portion (the drive shaft 180 and/or thepin 182), the coupling moves. And, in the axis L2, the free end portion150 A3 inclines to the free end 180 b 3 (disengaging angular position)(FIG. 25 (c)). And, in this state, the coupling 150 is passed by thedrive shaft 180, contacting to the free end 180 b 3, and is disengagedfrom the drive shaft 180 (FIG. 25 (d)). Thereafter, the cartridge (B)follows the process opposite from that of the mounting process describedin FIG. 20, and is taken out from the apparatus main assembly (A).

As will be apparent from the foregoing description, the angle of thepre-engagement angular position relative to the axis L1 is larger thanthe angle of the disengaging angular position relative to the axis L1.This is because it is preferable that the free end position 150A1 passesassuredly by the free end portion 180 b 3 in the pre-engagement angularposition in consideration of the dimensional tolerance of the parts atthe time of the engagement of the coupling. More particularly, it ispreferable that the gap exists between the coupling 150 and the free endportion 180 b 3 in the pre-engagement angular position (FIG. 22 (b)). Onthe contrary, at the time of the coupling disengagement, the axis L2inclines in interrelation with the dismounting operation of thecartridge in the disengaging angular position. Therefore, the coupling150 A3 moves along the free end portion 180 b 3. In other words, theupstream portion, with respect to the cartridge dismounting direction,of the coupling and the free end portion of the drive shaft are in thesubstantially same position (FIG. 25 (c)). For this reason, the angle ofthe pre-engagement angular position relative to the axis L1 is largerthan the angle of the disengaging angular position relative to the axisL1.

In addition, similarly to the case of mounting the cartridge (B) to theapparatus main assembly (A), the cartridge (B) can be taken outirrespective of the phase difference between the coupling 150 and thepin 182.

As shown in FIG. 22, in the rotational force transmitting angularposition of the coupling 150, the angle relative to the axis L1 of thecoupling 150 is such that in the state where the cartridge (B) ismounted to the apparatus main assembly (A), the coupling 150 receivesthe transmission of the rotational force from the drive shaft 180, andit rotates.

The rotational force transmitting angular position of the coupling 150,the rotational force for rotating the photosensitive drum is transmittedto the drum.

In addition, in the pre-engagement angular position of the coupling 150,the angular position relative to the axis L1 of the coupling 150 is suchthat it is in the state immediately before the coupling 150 engages withthe drive shaft 180 in the mounting operation to the apparatus mainassembly (A) of the cartridge (B). More particularly, it is the angularposition relative to the axis L1 which the downstream free end portion150A1 of the coupling 150 can pass by the drive shaft 180 with respectto the mounting direction of the cartridge (B).

In addition, the disengaging angular position of the coupling 150 is theangular position relative to the axis L1 of the coupling 150 at the timeof taking out the cartridge (B) from the apparatus main assembly (A), inthe case that the coupling 150 disengages from the drive shaft 180. Moreparticularly, as shown in FIG. 25, it is the angular position relativeto the axis L1 with which the free end portion 150 A3 of the coupling150 can pass by the drive shaft 180 with respect to the removingdirection of the cartridge (B).

In the pre-engagement angular position or the disengaging angularposition, the angle theta 2 which the axis L2 makes with the axis L1 islarger than the angle theta 1 which the axis L2 makes with the axis L1in the rotational force transmitting angular position. As for the angletheta 1, 0 degree is preferable. However, in this embodiment, if theangle theta 1 is less than about 15 degrees, the smooth transmission ofthe rotational force is accomplished. This is also one of the effects ofthis embodiment. As for the angle theta 2, the range of about 20-60degrees is preferable.

As has been described hereinbefore, the coupling is pivotably mounted tothe axis L1. And, the coupling 150 in the state in which it overlapswith the drive shaft 180 with respect to the direction of the axis L1can be disengaged from the drive shaft 180 because the coupling inclinescorrespondingly to the dismounting operation of the cartridge (B). Moreparticularly, by moving the cartridge (B) in the direction substantiallyperpendicular to the axial direction of the drive shaft 180, thecoupling 150 which covers the drive shaft 180 can be disengaged from thedrive shaft 180.

In the above described description, the receiving surface 150 f of thecoupling 150 or the projection 150 d contacts with the free end portion180 b (the pin 182) in interrelation with the movement of the cartridge(B) in the dismounting direction X6. By this, it has been described thatthe axis L1 starts the inclination to the dismounting directionupstream. However, the present invention is not limited to such anexample For example, the coupling 150 has a structure beforehand, sothat it is urged toward the upstream in the dismounting direction. And,corresponding to the movement of the cartridge (B), this urging forcestarts the inclination of the axis L1 toward the downstream in thedismounting direction. And, the free end 150 A3 passes by the free end180 b 3, and the coupling 150 disengages from the drive shaft 180. Inother words, the receiving surface 150 f in the upstream side withrespect to the dismounting direction or projection 150 d does notcontact with the free end portion 180 b, and therefore, it can bedisengaged from the drive shaft 180. For this reason, the any structurecan be applied if the axis L1 can be inclined in interrelation with thedismounting operation of the cartridge (B).

By the point of time immediately before the coupling 150 is mounted tothe drive shaft 180, the driven portion of the coupling 150 is inclined,so that it is inclines toward the downstream with respect to themounting direction. In other words, the coupling 150 is beforehand puton in the state of the pre-engagement angular position.

In the foregoing, the motion in the plane in the sheet of the drawing ofFIG. 25 has been described, but the motion may include the whirlingmotion as in the case of FIG. 22.

As to the structure therefor, the structure of any that will bedescribed in Embodiment 2 et seqq is usable.

Referring to FIG. 26 and FIG. 27, the description will be made about theother embodiment of the drum shaft. FIG. 26 is a perspective view of theneighborhood of the drum shaft. FIG. 27 illustrates a characteristicportion.

In the embodiment described above, the free end of the drum shaft 153 isformed into the spherical surface, and the coupling 150 is in contactwith the spherical surface thereof. However, as shown in FIGS. 26 (a)and 27 (a), the free end 1153 b of the drum shaft 1153 may be a flatsurface. In the case of this embodiment, the edge portion 1153 c of theperipheral surface thereof contacts the conic surface of the coupling150, by which the rotation is transmitted. Even with such a structure,the axis L2 can be assuredly inclined relative to the axis L1. In thecase of this embodiment, there is no necessity for the spherical surfacemachining. Therefore, the machining cost can be reduced.

In the embodiment described above, another rotational force transmittingpin is mounted to the drum shaft. However, as shown in FIGS. 26 (b) and27 (b), it is possible to mold the drum shaft 1253 and the pin 1253 cintegrally. In the case of integral molding using injection molding andso on, the geometrical latitude becomes high. In this case, the pin 1253c can be integrally formed with the drum shaft 1253. For this reason,the wide area of the drive transmitting portion 1253 d can be provided.Therefore, the running torque can be assuredly transmitted to the drumshaft made of the resin material. In addition, since integral molding isutilized, the manufacturing cost is reduced.

As shown in FIGS. 26 (c) and 27 (c), the opposite ends 1355 a 1, 1355 a2 of rotational force transmitting pin (rotational force receivingmember) 1355 are beforehand fixed by the press-fitting and so on to thestandby opening 1350 g 1 or 1350 g 2 of the coupling 1350. Thereafter,it is possible to insert the drum shaft 1353 which has a free endportion 1353 c 1, 1353 c 2 formed into a screw slotted shape (concave).At this time, in order to provide a pivotability of the coupling 1350,the engaging portion 1355 b of the pin 1355 relative to the free endportion (unshown) of the drum shaft 1353 is formed into a sphericalshape. Thus, the pin 1355 (rotational force applying portion) is fixedbeforehand. By this, the size of the opening 1350 g of the coupling 1350can be reduced. Therefore, the rigidity of the coupling 1350 can beincreased.

In the foregoing, the structure by which the inclination of the axis L1is made along the free end of the drum shaft has been described.However, as shown in FIGS. 26 (d), 26 (e), and 27 (d), it is possible toincline along the contact surface 1457 a of the contact member 1457 onthe axis of the drum shaft 1453. In this case, the free end surface 1453b of the drum shaft 1453 has a height comparable to the end surface ofthe contact member 1457. In addition, the rotational force transmittingpin (the rotational force receiving member) 1453 c projected beyond thefree end surface 1453 b is inserted into the standby opening 1450 g ofthe coupling 1450. The pin 1453 c contacts to the rotational forcetransmission surface (the rotational force transmitting portion) 1450 hof the coupling 1450. By this, the rotational force is transmitted tothe drum 107. In this manner, the contact surface 1457 a at the time ofthe coupling 1450 inclining is provided in the contact member 1457. Bythis, there is no necessity of processing the drum shaft directly.Therefore, the machining cost can be lowered.

In addition, similarly, the spherical surface at the free end may be amolded resin part of separate member. In this case, the machining costof the shaft can be lowered. This is because the configuration of theshaft to be processed by the cutting and so on can be simplified. Inaddition, when the range of the spherical surface at the axial free endis decreased, the range of the processing which requires high degree ofaccuracy can be made small. By this, the machining cost can be lowered.

Referring to FIG. 28, the description will be made about anotherembodiment of the drive shaft. FIG. 28 is perspective views of a driveshaft and a drum driving gear.

First, as shown in FIG. 28 (a), the free end of the drive shaft 1180 ismade into the flat surface 1180 b. By this, since the configuration ofthe shaft is simple, the machining cost can be lowered.

In addition, as shown in FIG. 28 (b), it is possible to mold therotational force applying portion (drive transmitting portion) 1280(1280c 1, 1280 c 2) integrally with the drive shaft 1280. When the driveshaft 1280 is the molded resin part, the rotational force applyingportion can be molded integrally. Therefore, the cost reduction can beaccomplished. Designated by 1280 b is the flat surface portion.

In addition, as shown in FIG. 28 (c), the range of the free end portion1380 b of the drive shaft 1380 is decreased. For this purpose, it ispossible to make the outer diameter of the shaft free end 1380 c smallerthan the outer diameter of the main part 1380 a. As described above, thefree end portion 1380 b requires a certain amount of accuracy, in orderto determine the position of the coupling 150. Therefore, the sphericalrange is limited only to the contact portion of the coupling. By this,the portion other than the surface where accuracy of finishing isrequired is omitted. By this, the machining cost is lowered. Inaddition, similarly, it is possible to cut the free end of theunnecessary spherical surface. Designated by 1382 is a pin (therotational force applying portion).

The positioning method of the photosensitive drum 107 with respect tothe direction of the axis L1 will be described. In other words, thecoupling 1550 is provided with a tapered surface (the inclined plane)1550 e, 1550 h. And, a force is produced in the thrust direction by therotation of the drive shaft 181. The positioning, with respect to thedirection of the axis L1, of the coupling 1550 and the photosensitivedrum 107 is effected by this thrust force. Referring to FIG. 29 and FIG.30, this will be described in detail. FIG. 29 is a perspective view anda top plan view of the coupling alone. FIG. 30 is an explodedperspective view which illustrates the drive shaft, the drum shaft, andthe coupling.

As shown in FIG. 29 (b), the rotational force receiving surface 1550 e(the inclined plane) (rotational force receiving portion) is inclined bythe angle α5 relative to the axis L2. When the drive shaft 180 rotatesin the direction T1, the pin 182 and the rotational force receivingsurface 1550 e contact to each other. Then, a component force is appliedto the coupling 1550 in the direction T2, and it moves in the directionT2. And, the coupling 1550 moves to the axial direction until thedriving shaft receiving surface 1550 f (FIG. 30a ) abuts to the free end180 b of the drive shaft 180. By this, the position of the coupling 1550with respect to the direction of the axis L2 is determined. In addition,the free end 180 b of the drive shaft 180 is formed into the sphericalsurface, and the receiving surface 1550 f has the conic surface.Therefore, with respect to the direction perpendicular to the axis L2,the position of the driven portion 1550 a relative to the drive shaft180 is determined. In cases where the coupling 1550 is mounted to thedrum 107, the drum 107 also moves to the axial direction depending onthe size of the force in which it is added in the direction T2. In thiscase, with respect to the longitudinal direction, the position of thedrum 107 relative to the apparatus main assembly is determined. The drum107 is mounted with play in the longitudinal direction thereof in thecartridge frame B1.

As shown in FIG. 29 (c), the rotational force transmission surface (therotational force transmitting portion) 1550 h is inclined by the angle α6 relative to the axis L2. When the coupling 1550 rotates in thedirection T1, the transmitting surface 1550 h and the pin 155 abutrelative to each other. Then, a component force is applied to the pin155 in the direction T2, and it moves in the direction T2. And, the drumshaft 153 moves until the free end 153 b of the drum shaft 153 contactsto the drum bearing surface 1550 i (FIG. 30 (b)) of the coupling 1550.By this, the position of the drum shaft 155 (the photosensitive drum)with respect to the direction of the axis L2 is determined. In addition,the drum bearing surface 1550 i has a conic surface, and the free end153 b of the drum shaft 153 is formed into a spherical surface.Therefore, with respect to the direction perpendicular to the axis L2,the position of the driving portion 1550 b relative to the drum shaft153 is determined.

The taper angles α5 and α6 are set to the degree with which the forceeffective to move the coupling and the photosensitive drum in the thrustdirection is produced. However, the forces thereof differ depending onthe running torque of the photosensitive drum 107. However, if there isprovided means which is effective to determine the position in thethrust direction, the taper angles α5 and α6 may be small.

As has been described hereinbefore, the taper for being drawn in thecoupling in the direction of the axis L2 and the conic surface fordetermining the position at the axis L2 with respect to theorthogonality direction are provided. By this, a position with respectto the direction of the axis L1 of the coupling and a position withrespect to the direction perpendicular to the axis L1, are determinedsimultaneously. In addition, the coupling can transmit the rotationalforce assuredly. Furthermore, as compared with the case where therotational force receiving surface (rotational force receiving portion)or the rotational force transmission surface (the rotational forcetransmitting portion) of the coupling does not have the taper angle asdescribed above, the contact between the rotational force applyingportion of the drive shaft and the rotational force receiving portion ofthe coupling can be stabilized. In addition, the contact abutmentbetween the rotational force receiving portion of the drum shaft and therotational force transmitting portion of the coupling can be stabilized.

However, the tapered surface (the inclined plane) for pulling in thecoupling in the direction of the axis L2 and the conic surface fordetermining the position of the axis L2 with respect to the orthogonaldirection may be omitted. For example, in place of the taper for drawingin the direction of the axis L2, it is possible to add a part for urgingthe drum in the direction of the axis L2. Hereinafter, as long as thereis no particular mentioning, the tapered surface and the conic surfaceare provided. In addition, the tapered surface and the conic surface areprovided also in the coupling 150 described above.

Referring to FIG. 31, the regulating means for regulating the incliningdirection relative to the cartridge of the coupling will be described.FIG. 31 (a) is a side view which illustrates the major part of thedriving side of the process cartridge, and FIG. 31 (b) is a sectionalview taken along S7-S7 of FIG. 31 (a).

In this embodiment, the coupling 150 and the drive shaft 180 of theapparatus main assembly can be more assuredly engaged by providing theregulating means.

In this embodiment, as the regulating means, the regulating portions1557 h 1 or 1557 h 2 are provided on the drum bearing member 1557. Thecoupling 150 can be regulated in swinging directions relative to thecartridge (B) by this regulating means. The structure is such that bythe time, immediately before the coupling 150 engages with the driveshaft 180, this regulating portion 1557 h 1 or 1557 h 2 is parallel tothe mounting direction X4 of the cartridge (B). In addition, theintervals D6 is slightly larger than the outer diameter D7 of thedriving portion 150 b of the coupling 150. By doing so, the coupling 150is pivotable only to the mounting direction X4 of the cartridge (B). Inaddition, the coupling 150 can be inclined in any direction relative tothe drum shaft 153. Therefore, irrespective of the phase of the drumshaft 153, the coupling 150 can be inclined in the regulated direction.Therefore, the opening 150 m of the coupling 150 can receive the driveshaft 180 more assuredly. By this, the coupling 150 is more assuredlyengageable with the drive shaft 180.

Referring to FIG. 32, another structure for regulating the incliningdirection of the coupling will be described. FIG. 32 (a) is aperspective view which illustrates the inside of the apparatus mainassembly driving side, and FIG. 32 (b) is a side view of a cartridge, asseen from the upstream with respect to the mounting direction X4.

The regulating portions 1557 h 1 or 1557 h 2 are provided in thecartridge (B) in the above described description. In this embodiment, apart of mounting guide 1630R1 of the driving side of the apparatus mainassembly (A) is a rib-like regulating portion 1630R1 a. The regulatingportion 1630R1 a is the regulating means for regulating the swingingdirections of the coupling 150. And, the structure is such that, whenthe user inserts the cartridge (B), the outer periphery of a connectingportion 150 c of the coupling 150 contacts to the upper surface 1630R1a-1 of the regulating portion 1630R1 a. By this, the coupling 150 isguided by the upper surface 1630R1 a-1. For this reason, the incliningdirection of the coupling 150 is regulated. In addition, similarly tothe embodiment described above, irrespective of the phase of the drumshaft 153, the coupling 150 is inclined in the direction in which itregulated.

The regulating portion 1630R1 a is provided below the coupling 150 inthe example shown in FIG. 32 (a). However, similarly to the regulatingportion 1557 h 2 shown in FIG. 31, the more assured regulation can beaccomplished when the regulating portion is added to the upper side.

As described above, it may be combined with the structure in which theregulating portion is provided in the cartridge (B). In this case, moreassured regulation can be accomplished.

However, in this embodiment, by which the means for regulating theinclining direction of the coupling may be omitted for example, thecoupling 150 is beforehand inclined downstream with respect to themounting direction of the cartridge (B). And, the driving shaftreceiving surface 150 f of the coupling is enlarged. By this, theengagement between the drive shaft 180 and the coupling 150 can beestablished.

In addition, in the foregoing description, the angle in thepre-engagement angular position of the coupling 150 relative to the drumaxix L1 is larger than the angle in the disengaging angular position(FIGS. 22 and 25). However, the present invention is not limited to suchan example.

Referring to FIG. 33, the description will be made. FIG. 33 is alongitudinal sectional view which illustrates the process for taking outthe cartridge (B) from the apparatus main assembly (A).

In the process for taking out the cartridge (B) from the apparatus mainassembly (A), the angle in the disengaging angular position (in thestate FIG. 33c ) of the coupling 1750 relative to the axis L1 may beequivalent to the angle in the pre-engagement angular position of thecoupling 1750 relative to the axis L1 at the time of the coupling 1750engaging. Here, the process in which the coupling 1750 disengages isshown by (a)-(b)-(c)-(d) in FIG. 33.

More particularly, the setting is such that, when the upstream free endportion 1750 A3 with respect to the dismounting direction X6 of thecoupling 1750 passes by the free end portion 180 b 3 of the drive shaft180, the distance between the free end portion 1750 A3 and the free endportion 180 b 3 is comparable as the distance at the time of thepre-engagement angular position. With such a setting, the coupling 1750can be disengaged from the drive shaft 180.

The other operations at the time of demounting the cartridge (B) are thesame as the above described operations, and therefore, the descriptionis omitted.

In addition, in the foregoing description, at the time of mounting thecartridge (B) to the apparatus main assembly (A), the downstream freeend with respect to the mounting direction of the coupling is closer tothe drum shaft than the free end of the drive shaft 180. However, thepresent invention is not limited to such an example.

Referring to FIG. 34, the description will be made. FIG. 34 is alongitudinal sectional view for illustrating the mounting process of thecartridge (B). As shown in FIG. 34, in the state of (a) the mountingprocess of the cartridge (B), in the direction of the axis L1, thedownstream free end position 1850A1 with respect to the mountingdirection X4 is closer to the direction of the pin 182 (the rotationalforce applying portion) than the drive shaft free end 180 b 3. In thestate of (b), the free end position 1850A1 is contacted to the free endportion 180 b. At this time, the free end position 1850A1 moves towardthe drum shaft 153 along the free end portion 180 b. And, the free endposition 1850A1 passes by the free end portion 180 b 3 of the driveshaft 180 at this position, the coupling 150 takes the pre-engagementangular position (FIG. 34 (c)). And, finally the engagement between thecoupling 1850 and the drive shaft 180 is established ((rotational forcetransmitting angular position) FIG. 34 (d)).

An example of this embodiment will be described.

First, the shaft diameter of the drum shaft 153 is ΦZ1, the shaftdiameter of the pin 155 is ΦZ2, and the length is Z3 (FIG. 7 (a)). Themaximum outer diameter of the driven portion 150 a of the coupling 150is ΦZ4 the diameter of a phantom circle C1 which passes the inner endsof the projections 150 d 1 or 150 d 2 or 150 d 3, 150 d 4 is ΦZ5, andthe maximum outer diameter of the driving portion 150 b is ΦZ6 (FIG. 8(d), (f)). The angle formed between the coupling 150 and the receivingsurface 150 f is α2, and the angle formed between the coupling 150 andthe receiving surface 150 i is α1. A shaft diameter of the drive shaft180 is ΦZ7, the shaft diameter of the pin 182 is ΦZ8, and the length isZ9 (FIG. 17 (b)). In addition, the angle relative to the axis L1 in therotational force transmitting angular position is β1, the angle in thepre-engagement angular position is β2, and the angle in the disengagingangular position is β3. In this example, Z1=8 mm; Z2=2 mm; Z3=12 mm;Z4=15 mm; Z5=10 mm; Z6=19 mm; Z7=8 mm; Z8=2 mm; Z9=14 mm; α1=70 degrees;α2=120 degrees; β1=0 degree; β2=35 degrees; β3=30 degrees.

It has been confirmed with these settings, the engagement between thecoupling 150 and the drive shaft 180 is possible. However, thesesettings do not limit the present invention. In addition, the coupling150 can transmit the rotational force to the drum 107 with highprecision. The values given above are the examples, and the presentinvention is not limited to these values.

In addition, in this embodiment, the pin (the rotational force applyingportion) 182 is disposed in the range of 5 mm from the free end of thedrive shaft 180. In addition, the rotational force receiving surface(rotational force receiving surface) 150 e provided in the projection150 d is disposed at the range of 4 mm from the free end of the coupling150. In this manner, the pin 182 is disposed at the free end side of thedrive shaft 180 in addition, the rotational force receiving surface 150e is disposed at the free end side of the coupling 150.

By this, at the time of mounting the cartridge (B) to the apparatus mainassembly (A), the drive shaft 180 and the coupling 150 can engagesmoothly with each other. In more detail, the pin 182 and the rotationalforce receiving surface 150 e can engage smoothly with each other.

In addition, at the time of demounting the cartridge (B) from theapparatus main assembly (A), the drive shaft 180 and the coupling 150can disengage smoothly from each other. More particularly, the pin 182and the rotational force receiving surface 150 e can disengage smoothlyfrom each other.

The values are the examples, and the present invention is not limited tothese values. However, the effects described above are furtherenhance(d) by the pin (rotational force applying portion) 182 and therotational force receiving surface 150 e being disposed in thesenumerical value ranges.

As described in the foregoing, in the described embodiment, the couplingmember 150 is capable of taking the rotational force transmittingangular position for transmitting the rotational force for rotating theelectrophotographic photosensitive drum to the electrophotographicphotosensitive drum and the disengaging angular position in which thecoupling member 150 is inclined away from the axis of theelectrophotographic photosensitive drum from the rotational forcetransmitting angular position. When the process cartridge is dismountedfrom the main assembly of the electrophotographic image formingapparatus in a direction substantially perpendicular to the axis of theelectrophotographic photosensitive drum, the coupling member moves fromthe rotational force transmitting angular position to the disengagingangular position. When the process cartridge is mounted to the mainassembly of the electrophotographic image forming apparatus in adirection substantially perpendicular to the axis of theelectrophotographic photosensitive drum, the coupling member moves fromthe disengaging angular position to the rotational force transmittingangular position. This applies to the following embodiments, althoughthe following embodiment 2 is related with the dismounting only.

[Embodiment 2]

Referring to FIG. 35-FIG. 40, the second embodiment to which applied thepresent invention will be described.

In the description of this embodiment, the same reference numerals as inEmbodiment 1 are assigned to the elements having the correspondingfunctions in this embodiment, and the detailed description thereof isomitted for simplicity. This applies also about the other embodimentdescribed in the below.

The this embodiment is effective not only for the case of the mountingand the dismounting of the cartridge (B) relative to the apparatus mainassembly (A) but also the case of the dismounting only of the cartridge(B) from the apparatus main assembly (A).

More particularly, when the drive shaft 180 stops, the drive shaft 180is stopped with the predetermined phase by the control of the apparatusmain assembly (A) in other words, it stops so that the pin 182 maybecome at a predetermined position. Moreover, the phase of the coupling14150 (150) is set in alignment with the phase of the stopped driveshaft 180 for example, the position of standing-by portion 14150 k (150k) is set so that it may align with the stop position of the pin 182with such a setting, at the time of mounting the cartridge (B) to theapparatus main assembly (A), even if the coupling 14150 (150) is notpivoted, it will become in the state of being opposed to the drive shaft180. And, the rotational force from the drive shaft 180 is transmittedto the coupling 14150 (150) by the drive shaft 180 rotating. By this,the coupling 14150 (150) can rotate with high precision.

However, this embodiment is effective at the time of demounting thecartridge (B) from the apparatus main assembly (A) by moving in thedirection substantially perpendicular to the direction of the axis L3.This is because even if the drive shaft 180 stops with the predeterminedphase, the pin 182 and rotational force receiving surface 14150 e 1,14150 e 2 (150 e) are in engagement relative to each other. For thisreason, in order to disengage the coupling 14150 (150) from the driveshaft 180, the coupling 14150 (150) needs to pivot.

In addition, in the embodiment 1 described above, at the time ofmounting the cartridge (B) to the apparatus main assembly (A) and at thetime of demounting it, the coupling 14150 (150) pivots. Therefore, thecontrol of the apparatus main assembly (A) described above isunnecessary, and, at the time of mounting the cartridge (B) to theapparatus main assembly (A), it is not necessary to set the phase of thecoupling 14150 (150) in accordance with the phase of the stopped driveshaft 180 beforehand.

The description will be made referring to the drawing.

FIG. 35 is a perspective view which illustrates the phase control meansfor the drive shaft, the driving gear, and the drive shaft of theapparatus main assembly. FIG. 36 is a perspective view and a top planview of the coupling. FIG. 37 is a perspective view which illustratesthe mounting operation of the cartridge. FIG. 38 is a top plan view, asseen from the direction of the mounting direction at the time of thecartridge mounting. FIG. 39 is a perspective view which illustrates inthe state of the drive stop of the cartridge (the photosensitive drum).FIG. 40 is a longitudinal sectional view and a perspective view whichillustrate the operation for taking out the cartridge.

In this embodiment, the description will be made about the cartridgedetachably mountable to apparatus main assembly (A) provided with thecontrol means (unshown) which can control the phase of the stop positionof the pin 182. The one end side (an unshown photosensitive drum 107side) of the drive shaft 180 is the same as that of the firstembodiment, as shown in FIG. 35 (a), and therefore, the description isomitted. On the other hand, as shown in FIG. 35 (b), the other end side(the opposite side of the unshown photosensitive drum 107 side) isprovided with a flag 14195 projected from the drive shaft 180 outerperiphery of the drive shaft 180. And, the flag 14195 passes through thephoto-interruptor 14196 fixed to the apparatus main assembly (A) by therotation thereof. And, a control means (unshown) effects the control, sothat after the rotation (for example, image forming rotation) of thedrive shaft 180, when the flag 14195 interrupts the photo-interruptor14196 first, a motor 186 stops. By this, the pin 182 stops at apredetermined position relative to the rotation axis of the drive shaft180. As for the motor 186, in the case of this embodiment, it isdesirably a stepping motor with which the positioning control is easy.

Referring to FIG. 36, the coupling used in this embodiment will bedescribed.

The coupling 14150 mainly comprises three portions. As shown in FIG. 36(c), they are a driven portion 14150 a for receiving the rotationalforce from the drive shaft 180, a driving portion 14150 b fortransmitting the rotational force to the drum shaft 153, and aconnecting portion 14150 c which connects the driven portion 14150 a andthe driving portion 14150 b with each other.

The driven portion 14150 a has a drive shaft inserting portion 14150 mconstituted by 2 surfaces which expand in a direction away from an axisL2. In addition, the driving portion 14150 b has a drum shaft insertingportion 14150 v constituted in the two surfaces which expand away fromthe axis L2.

The inserting portion 14150 m has a tapered driving shaft receivingsurfaces 14150 f 1 or 14150 f 2. And, each end surface is provided witha projection 14150 d 1 or 14150 d 2. The projections 14150 d 1 or 14150d 2 are disposed on a circumference about the axis L2 of the coupling14150. The receiving surfaces 14150 f 1, 14150 f 2 constitute a recess14150 z, as shown in the Figure. In addition, as shown in FIG. 36 (d),the downstream of the projection 14150 d 1,14150 d 2 with respect to theclockwise direction is provided with a rotational force receivingsurface (rotational force receiving portion) 14150 e (14150 e 1, 14150 e2). A pin (rotational force applying portion) 182 abuts to thisreceiving surface 14150 e 1, 14150 e 2. By this, the rotational force istransmitted to the coupling 14150. An interval (W) between the adjacentprojections 14150 d 1-d 2 is larger than the outer diameter of the pin182, in order to permit the entrance of the pin 182. This interval isthe standing-by portions 14150 k.

In addition, the inserting portion 14150 v is constituted by the twosurfaces 14150 i 1, 14150 i 2. And, the standby openings 14150 g 1 or14150 g 2 are provided in these surfaces 14150 i 1, 14150 i 2 (the FIG.36a FIG. 36e ). In addition, in FIG. 36 (e), at the upstream of theopenings 14150 g 1 or 14150 g 2 with respect to the clockwise direction,a rotational force transmission surface (rotational force transmittingportion) 14150 h (14150 h 1 or 14150 h 2) is provided. And, as describedabove, the pin (the rotational force receiving portion) 155 a contactswith the rotational force transmission surfaces 14150 h 1 or 14150 h 2.By this, the rotational force is transmitted to the photosensitive drum107 from the coupling 14150.

With the shape of coupling 1415, the coupling is over the free end ofthe driving shaft in the state that the cartridge is mounted to the mainassembly of the apparatus.

And, with the similar structure as the structure described by the firstembodiment, the coupling 14150 can be inclined in any direction relativeto the drum shaft 153.

Referring to FIG. 37 and FIG. 38, a mounting operation of the couplingwill be described. FIG. 37 (a) is a perspective view which illustratesthe state before the coupling is mounted. FIG. 37 (b) is a perspectiveview which illustrates the state where the coupling engaged. FIG. 38 (a)is a top plan view thereof, as seen from the mounting direction. FIG. 38(b) is a top plan view thereof, as seen from the top relative to themounting direction.

An axis L3 of the pin (rotational force applying portion) 182 isparallel to the mounting direction X4 by the control means describedabove. In addition, as to the cartridge, the phase aligns so that thereceiving surfaces 14150 f 1 and 14150 f 2 are opposite from each otherin the direction perpendicular to the mounting direction X4 (FIG. 37(a)). As a structure for aligning the phase, any one side of thereceiving surfaces 14150 f 1 or 14150 f 2 is aligned with a mark 14157 zprovided on the bearing member 14157, as shown in the Figure, forexample. This is carried out before shipping the cartridge from theplant. However, the user may carry out, before mounting the cartridge(B) to the apparatus main assembly. In addition, other phase adjustingmeans may be used. By doing so, the coupling 14150 and the drive shaft180 (the pin 182) are not interfered with each other with respect to themounting direction, as shown in FIG. 38 (a), in the positional relation.Therefore, the coupling 14150 and the drive shaft 180 are engageablewithout the problem (FIG. 37 (b)). And, the drive shaft 180 rotates inthe direction X8, so that the pin 182 contacts to the receiving surface14150 e 1, 14150 e 2. By this, the rotational force is transmitted tothe photosensitive drum 107.

Referring to FIG. 39 and FIG. 40, the description will be made as to theoperation in which the coupling 14150 disengages from the drive shaft180 in interrelation with the operation for taking out the cartridge (B)from the apparatus main assembly (A). The phase of the pin 182 relativeto the drive shaft 180 stops at the predetermined position by thecontrol means. As described above, when the easiness of the mounting ofthe cartridge (B) is considered, it is desirable for the pin 182 to stopwith the phase parallel to the cartridge dismounting direction X6 (FIG.39b ). The operation at the time of taking out the cartridge (B) isillustrated in FIG. 40. In this state (FIG. 40(a 1) and (b 1)), thecoupling 14150 takes the rotational force transmitting angular positionand the axis L2 and the axis L1 are substantially co-axial with eachother. At this time, similarly to the case of mounting the cartridge(B), the coupling 14150 can be inclined in any direction relative to thedrum shaft 153 (FIG. 40 a 1, FIG. 40 b 1). Therefore, the axis L2inclines in the direction opposite from the dismounting directionrelative to the axis L1 in interrelation with the dismounting operationof the cartridge (B). More particularly, the cartridge (B) is demountedin the direction (the direction of the arrow X6) substantiallyperpendicular to the axis L3. And, in the dismounting process of thecartridge, the axis L2 is inclined until the free end 14150 A3 of thecoupling 14150 becomes along the free end 180 b of the drive shaft 180(the disengaging angular position). Or, it is inclined until the axis L2comes to the drum shaft 153 side with respect to the free end portion180 b 3 (FIG. 40(a 2), FIG. 40(b 2)). In this state, the coupling 14150is passed by near the free end portion 180 b 3. By doing so, thecoupling 14150 is demounted from the drive shaft 180.

In addition, as shown in FIG. 39 (a), the axis of the pin 182 may stopin the state perpendicular to the cartridge dismounting direction X6.The pin 182 usually stops at the position shown in FIG. 39 (b) by thecontrol of the control means. However, the voltage source of the device(the printer) may become OFF and the control means may not work. The pin182 may stop at the position as shown in FIG. 39 (a) in such a case.However, even in such a case, the axis L2 is inclined relative to theaxis L1 similarly to the above described case, and the removal operationis possible. When the device is in the state of the drive stop, the pin182 is in the downstream beyond the projection 14150 d 2 with respect tothe dismounting direction X6. Therefore, the free end 14150 A3 of theprojection 14150 d 1 of the coupling passes the drum shaft 153 sidebeyond the pin 182 by the axis L2 inclining. By this, the coupling 14150is demounted from the drive shaft 180.

As has been described hereinbefore, even if it is the case where thecoupling 14150 is engaged relative to the drive shaft 180 by a certainmethod on the occasion of the mounting of the cartridge (B) the axis L2inclines relative to the axis L1 in the case of the dismountingoperation. By this, the coupling 14150 can be demounted from the driveshaft 180 only by such dismounting operation.

As has been described hereinbefore, according to this embodiment 2, thisembodiment is effective even for the case of demounting the cartridgefrom the main assembly of the apparatus, in addition to the case ofmounting and demounting the cartridge (B) relative to the apparatus mainassembly (A).

[Embodiment 3]

Referring to FIG. 41-FIG. 45, a third embodiment will be described.

FIG. 41 is a sectional view which illustrates a state where a door of anapparatus main assembly A is open. FIG. 42 is a perspective view whichillustrates a mounting guide. FIG. 43 is the enlarged view of a drivingside surface of the cartridge. FIG. 44 is a perspective view, as seenfrom a driving side, of the cartridge. FIG. 45 shows a view whichillustrates a state of inserting the cartridge into an apparatus mainassembly.

In this embodiment, for example, as in the case of the clamshell typeimage forming device, the cartridge is mounted downwardly. A typicalclamshell type image forming apparatus is shown in FIG. 41. Theapparatus main assembly A2 comprises a lower casing D2 and an uppercasing E2. And, the upper casing E2 is provided with a door 2109 and aninside exposure device 2101 of the door 2109. Therefore, when the uppercasing E2 is opened upward, the exposure device 2101 retracts. And, anupper portion of the cartridge set portion 2130 a is opened. When theuser mounts the cartridge B-2 to a set portion 2130 a, the user dropsthe cartridge B-2 on X4B downward. The mounting completes with this, andtherefore, the mounting of the cartridge is easy. In addition, the jamclearance operation of the adjacent a fixing device 105 can effect fromthe device upper portion. Therefore, it excels in the easiness of thejam clearance. Here, the jam clearance is the operation for a removing arecording material 102 jammed in the course of the feeding.

More specifically, the set portion for the cartridge B-2 will bedescribed. As shown in FIG. 42, the image forming device A2 is providedwith a mounting guide 2130R in a driving side, and is provided with amounting guide unshown in a non-driving side opposed to it As mountingmeans 2130. The set portion 2130 a is formed as the space surrounded bythe guides to oppose. The rotational force is transmitted to thecoupling 150 of the cartridge B-2 provided at this set portion 2130 afrom the apparatus main assembly A.

The mounting guide 2130R is provided with a groove 2130 b which extendsin the perpendicular direction substantially. In addition, an abuttingportion 2130Ra for determining the cartridge B-2 at the predeterminedposition is provided in the lowermost portion thereof. In addition, adrive shaft 180 projects from the groove 2130 b. In the state where thecartridge B-2 is positioned in the predetermined position, the driveshaft 180 transmits the rotational force to the coupling 150 from theapparatus main assembly A. In addition, in order to position thecartridge B-2 in the predetermined position assuredly, an urging spring2188R is provided in the lower part of the mounting guide 2130R. By thestructure described above, the cartridge B-2 is positioned in the setportion 2130 a.

As shown in FIG. 43 and FIG. 44, the cartridge B-2 is provided with thecartridge side mounting guides 2140R1 and 2140R2. The orientation of thecartridge B-2 is stabilized by this guide at the time of the mounting.And, the mounting guide 2140R1 is integrally formed on the drum bearingmember 2157. In addition, the mounting guide 2140R2 is providedsubstantially above the mounting guide 2140R1. And, the guide 2140R2 isprovided in the second frame 2118, and it is in the form of a rib.

The mounting guides 2140R1, 2140R2 of the cartridge B-2 and the mountingguide 2130R of the apparatus main assembly A2 have the structuresdescribed above. More particularly, it is the same as that of thestructure of the guide which has been described in conjunction withFIGS. 2 and 3. In addition, the structure of the guide of the other endis also the same. Therefore, the cartridge B-2 is mounted while beingmoved to the apparatus main assembly A2 in the direction substantiallyperpendicular to the direction of the axis L3 of the drive shaft 180,and, in addition, it is similarly demounted from the apparatus mainassembly A2.

As shown in FIG. 45, at the time of mounting the cartridge B-2, theupper casing E2 is clockwisely rotated about a shaft 2109 a and, theuser brings the cartridge B-2 to the upper portion of the lower casingD2. At this time, the coupling 150 is inclined downwardly by the weightFIG. 43. In other words, the axis L2 of the coupling inclines relativeto the drum axix L1 so that the driven portion 150 a of the coupling 150may face down the pre-engagement angular position.

In addition, as has been described with respect to Embodiment 1, FIGS. 9and 12, it is desirable to provide the semi-circular retention rib 2157e FIG. 43. In this embodiment, the mounting direction of the cartridgeB-2 is downward. Therefore, the rib 2157 e is disposed in the lowerpart. By this, as has been described with respect to Embodiment 1, theaxis L1 and the axis L2 are pivotable relative to each other, and theretention of the coupling 150 is accomplished. The retention ribprevents the coupling 150 from separating from the cartridge B-2. Whenthe coupling 150 is mounted to the photosensitive drum 107, it ispreventing separation from the photosensitive drum 107 k.

In this state, as shown in FIG. 45, the user lowers the cartridge B-2downwardly, aligning the mounting guides 2140R1, 2140R2 of the cartridgeB-2 with the mounting guides 2130R of the apparatus main assembly A2.The cartridge B-2 can be mounted to the set portion 2130 a of theapparatus main assembly A2 only by this operation. In this mountingprocess, similarly to Embodiment 1, FIG. 22, the coupling 150 can beengaged with the drive shaft 180 of the apparatus main assembly (thecoupling takes the rotational force transmitting angular position inthis state). More particularly, by moving in cartridge B-2 in thedirection substantially perpendicular to the direction of the axis L3 ofthe drive shaft 180, the coupling 150 is engaged with the drive shaft180. In addition, at the time of demounting the cartridge, similarly toEmbodiment 1, the coupling 150 can be disengaged from the drive shaft180 only by the operation which demounts the cartridge (the couplingmoves to the disengaging angular position from the rotational forcetransmitting angular position, FIG. 25). More particularly, by movingthe cartridge B-2 in the direction substantially perpendicular to thedirection of the axis L3 of the drive shaft 180, the coupling 150 isdisengaged from the drive shaft 180.

As has been described hereinbefore, since the coupling inclinesdownwardly by the weight when downwardly mounting the cartridge to theapparatus main assembly, it can engage with the drive shaft of theapparatus main assembly assuredly.

In this embodiment, the clamshell type image forming device has beendescribed. However, the present invention is not limited to such anexample. For example, the present embodiment can be applied if themounting direction of the cartridge is downward. In addition, themounting path thereof is not limited to straight downward. For example,it may be inclined downward in initial mounting stage of the cartridge,and it may become downward finally. The present embodiment is effectiveif the mounting path immediately before reaching the predeterminedposition (the cartridge set portion) is downward.

[Embodiment 4]

Referring to FIG. 46-FIG. 49, the fourth embodiment of the presentinvention will be described.

In this embodiment, means to maintain the axis L2 at the inclined staterelative to the axis L1 will be described.

Only the member relating to the description of this portion of thepresent embodiment is shown in the drawing, and the other members areomitted. It is similar also in the other embodiments as will bedescribed hereinafter.

FIG. 46 is a perspective view which illustrates a coupling lockingmember (this is peculiar to the present embodiment) pasted on the drumbearing member. FIG. 47 is an exploded perspective view whichillustrates the drum bearing member, the coupling, and the drum shaft.FIG. 48 is an enlarged perspective view of a major part of the drivingside of the cartridge. FIG. 49 is a perspective view and a longitudinalsectional view which illustrate an engaged state between the drive shaftand the coupling.

As shown in FIG. 46, the drum bearing member 3157 has a space 3157 bwhich surrounds a part of coupling. A coupling locking member 3159 as amaintaining member for maintaining the inclination of the coupling 3150is pasted on a cylinder surface 3157 i which constitutes the spacethereof. As will be described hereinafter, this locking member 3159 is amember for maintaining temporarily the state where the axis L2 inclinesrelative to the axis L1. In other words, as shown in FIG. 48, the flangeportion 3150 j of the coupling 3150 contacts to this locking member3159. By this, the axis L2 maintains the state of inclining toward thedownstream with respect to the mounting direction (X4) of the cartridgerelative to the axis L1 (FIG. 49 (a 1)). Therefore, as shown in FIG. 46,the locking member 3159 is disposed on the upstream cylinder surface3157 i of the bearing member 3157 with respect to the mounting directionX4. As the material of the locking member 3159, the material which has arelatively high coefficient of friction, such as the rubber and theelastomer, or the elastic materials, such as the sponge and the flatspring, are suitable. This is because, the inclination of the axis L2can be maintained by the frictional force, the elastic force, and so on.In addition, similarly to Embodiment 1 (it illustrates in FIG. 31), thebearing member 3157 is provided with the inclining direction regulationrib 3157 h. The inclining direction of the coupling 3150 can beassuredly determined by this rib 3157 h. In addition, the flange portion3150 j and the locking member 3159 can contact relative to each othermore assuredly. Referring to FIG. 47, the assembly method of thecoupling 3150 will be described. As shown in FIG. 47, the pin(rotational force receiving portion) 155 enters the standing-by space3150 g of the coupling 3150. In addition, a part of coupling 3150 isinserted into the space portion 3157 b which the drum bearing member3157 has. At this time, preferably, a distance D12 between an innersurface end of the rib 3157 e and the locking member 3159 is set, sothat it is larger than maximum outer diameter of the driven portion 3150a ΦD10. In addition, the distance D12 is set so that it is smaller thanthe maximum outer diameter of the driving portion 3150 b ΦD11. By this,the bearing member 3157 can be assembled straight. Therefore, theassembling property is improved. However, the present embodiment is notlimited to this relation.

Referring to FIG. 49, the engaging operation (a part of mountingoperation of the cartridge) for engaging the coupling 3150 with thedrive shaft 180 will be described. FIGS. 49 (a 1) and (b 1) illustratethe state immediately before the engagement, and FIGS. 49 (a 2) and (b2) illustrate the state of the completion of the engagement.

As shown in FIG. 49 (a 1) and FIG. 49 (b 1), the axis L2 of the coupling3150 inclines toward the downstream with respect to the mountingdirection X4 relative to the axis L1 beforehand by the force of thelocking member 3159 (pre-engagement angular position). By thisinclination of the coupling 3150, by, in the direction of the axis L1,the downstream (with respect to the mounting direction) free end portion3150A1 is closer to the photosensitive drum 107 direction side than thedrive shaft free end 180 b 3. And, the upstream (with respect to themounting direction) free end portion 3150A2 is closer to the pin 182than the free end 180 b 3 of the drive shaft 180 in addition, at thistime, as has been described in the foregoing, the flange portion 3150 jis contacted to the locking member 3159. And, the inclined state of theaxis L2 is maintained by the frictional force thereof.

Thereafter, the cartridge B moves to the mounting direction X4. By this,the free end surface 180 b or the free end of the pin 182 contacts tothe driving shaft receiving surface 3150 f of the coupling 3150. And,the axis L2 approaches to the direction in parallel with the axis L1 bythe contact force (mounting force of the cartridge) thereof. At thistime, the flange portion 3150 j is departed from the locking member3159, and becomes into the non-contact state. And, finally, the axis L1and the axis L2 are substantially co-axial with each other. And, thecoupling 3150 is in the waiting (stand-by) state for transmitting therotational force (FIG. 49 (a 2), (b 2)). (rotational force transmittingangular position).

Similarly to Embodiment 1, from the motor 186, the rotational force istransmitted through the drive shaft 180 to the coupling 3150, the pin(rotational force receiving portion) 155, the drum shaft 153, and thephotosensitive drum 107. The axis L2 is substantially co-axial with theaxis L1 at the time of the rotation. Therefore, the locking member 3159is not in contact with the coupling 3150. Therefore, the locking member3159 does not affect the rotation of the coupling 3150.

In addition, the operations follow the step similar to Embodiment 1 inthe process in which the cartridge B is taken out from the apparatusmain assembly A (FIG. 25). In other words, the free end portion 180 b ofthe drive shaft 180 pushes the driving shaft receiving surface 3150 f ofthe coupling 3150. By this, the axis L2 inclines relative to the axisL1, and the flange portion 3150 j is brought into contact to the lockingmember 3159. By this, the inclined state of the coupling 3150 ismaintained again. In other words, the coupling 3150 moves to thepre-engagement angular position from the rotational force transmittingangular position.

As has been described hereinbefore, the inclined state of the axis L2 ismaintained by the locking member 3159 (maintaining member). By this, thecoupling 3150 can be more assuredly engaged with the drive shaft 180.

In this embodiment, the locking member 3159 is pasted on the upstreammost portion, with respect to cartridge mounting direction X4, of theinner surface 3157 i of the bearing member 3157. However, the presentinvention is not limited to this example. For example, when the axis L2inclines, any position which can maintain the inclined state thereof isusable.

In addition, in this embodiment, the locking member 3159 is contacted tothe flange portion 3150 j provided in the driving portion 3150 b (FIG.49 (b 1)) side. However, the contact position may be the driven portion3150 a.

In addition, the locking member 3159 used in this embodiment is aseparate member in the bearing member 3157. However, the presentembodiment is not limited to this example. For example, the lockingmember 3159 may be integrally molded with the bearing member 3157 (forexample, two-color molding). Or, the bearing member 3157 may be directlycontacted to the coupling 3150 in place of the locking member 3159. Orthe surface thereof may be roughened for the purpose of raising thecoefficient of friction.

In addition, in this embodiment, the locking member 3159 is pasted onthe bearing member 3157. However, if the locking member 3159 is themember fixed to the cartridge B, it may be pasted on any position.

[Embodiment 5]

Referring to FIG. 50-FIG. 53, the fifth embodiment of the presentinvention will be described.

In the present embodiment, another means for maintaining in the state ofinclining the axis L2 relative to the axis L1 will be described.

FIG. 50 is an exploded perspective view of the coupling urging member(it is peculiar to the present embodiment) mounted to the drum bearingmember. FIG. 51 is an exploded perspective view which illustrates thedrum bearing member, the coupling, and the drum shaft. FIG. 52 is anenlarged perspective view of a major part of the driving side of thecartridge. FIG. 53 is a perspective view and a longitudinal sectionalview which illustrate the drive shaft and the engaged state between thecoupling.

As shown in FIG. 50, a retaining hole 4157 j is provided in theretention rib 4157 e of the drum bearing member 4157. A coupling urgingmembers 4159 a, 4159 b as a maintaining member for maintaining theinclination of the coupling 4150 in the retaining hole 4157 j thereofare mounted. The urging members 4159 a, 4159 b urge the coupling 4150,so that the axis L2 inclines toward the downstream with respect to themounting direction of the cartridge B-2 relative to the axis L1. Eachurging member 4159 a, 4159 b is a coiled compression spring (elasticmaterial). As shown in FIG. 51, the urging members 4159 a, 4159 b urgethe flange portion 4150 j of the coupling 4150 toward the axis L1 (arrowof FIG. 51 an X13). The contact position where the urging memberscontact with the flange portion 4150 j is the downstream of the centerof the drum shaft 153 with respect to the cartridge mounting directionX4. Therefore, as for the axis L2, the driven portion 4150 a sideinclines toward the downstream with respect to the mounting direction(X4) of the cartridge relative to the axis L1 by the elastic force bythe urging member 4159 a, 4159 b (FIG. 52).

In addition, as shown in FIG. 50, the coupling side free end of eachurging member 4159 a, 4159 b which is the coil spring is provided with acontact member 4160 a, 4160 b. The contact member 4160 a, 4160 bcontacts the flange portion 4150 j. Therefore, the material of thecontact member 4160 a, 4160 b is preferably material of the highslidability. In addition, by using such the material, as will bedescribed hereinafter, at the time of the rotational force transmission,the influence to the rotation of the coupling 4150 of an urging force bythe urging member 4159 a, 4159 b is lessened. However, if the loadrelative to the rotation is sufficiently small, and the coupling 4150satisfactorily rotates, the contact members 4160 a, 4160 b is not beinevitable).

In the present embodiment, two urging members are provided. However, ifthe axis L2 can incline toward the downstream with respect to themounting direction of the cartridge relative to the axis L1, the numberof the urging members may be any. For example, in the case of the singleurging member, as for the energizing position, it is desirably thedownstream most position with respect to the mounting direction X4 ofthe cartridge. By this, the coupling 4150 can be stably inclined towardthe downstream with respect to the mounting direction.

In addition, the urging member is a compression coil spring in thepresent embodiment. However, as the urging member, if an elastic forcecan be produced as with the flat spring, the torsion spring, the rubber,the sponge, and so on, it may be any. However, in order to incline theaxis L2, a certain amount of stroke is required. Therefore, as with thecoil spring etc, it is desirable that the stroke can be provided.

Referring to FIG. 51, the description will be made about the mountingmethod of the coupling 4150.

As shown in FIG. 51, the pin 155 enters the standing-by space 4150 g ofthe coupling 4150. And, a part of coupling 4150 is inserted into thespace 4157 b of the drum bearing member 4157. At this time, as has beendescribed hereinbefore, the urging members 4159 a, 4159 b push theflange portion 4157 j onto the predetermined position through thecontact member 4160 a, 4160 b. The screw (4158 a of FIG. 52, 4158 b) isthreaded into the hole 4157 g 1 or 4157 g 2 provided in the bearingmember 4157, by which, the bearing member 4157 is fixed to the secondframe 118. By this, the urging force to the coupling 4150 by the urgingmember 4159 a, 4159 b can be assured. And, the axis L2 is inclinedrelative to the axis L1 (FIG. 52).

Referring to FIG. 53, the operation (a part of mounting operation of thecartridge) of engaging the coupling 4150 with the drive shaft 180 willbe described. FIGS. 53 (a 1) and (b 1) illustrate the state immediatelybefore the engagement, FIGS. 53 (a 2) and (b 2) illustrate the state ofthe engagement completion, and FIG. 53 (c 1) illustrates the statetherebetween.

In FIGS. 53 (a 1) and (b 1), the axis L2 of the coupling 4150 inclinestoward the mounting direction X4 relative to the axis L1 beforehand(pre-engagement angular position). By the coupling 4150 inclining, thedownstream free end position 4150A1 with respect to the direction of theaxis L1 is closer to the photosensitive drum 107 than the free end 180 b3. In addition, the free end position 4150A2 is closer to the pin 182than the free end 180 b 3. In other words, as has been describedhereinbefore, the flange portion 4150 j of the coupling 4150 is pressedby the urging member 4159. Therefore, the axis L2 is inclined relativeto the axis L1 by the urging force thereof.

Thereafter, by the cartridge B moving to the mounting direction X4, thefree end surface 180 b or the free end (the main assembly side engagingportion) of the pin (rotational force applying portion) 182 is broughtinto contact to the driving shaft receiving surface 4150 f or theprojection 4150 d of the coupling 4150 (the cartridge side contactportion). FIG. 53 (c 1) illustrates the state where the pin 182 is incontact with the receiving surface 4150 f. And, the axis L2 approachestoward the direction in parallel with the axis L1 by the contact force(mounting force of the cartridge). Simultaneously, the pressing portion4150 j 1 pressed by the elastic force of the spring 4159 provided in theflange portion 4150 j moves in the compression direction of the spring4159. And, finally, the axis L1 and the axis L2 becomes co-axial. And,the coupling 4150 takes the standby position for effecting thetransmission of the rotational force (FIG. (rotational forcetransmitting angular position) 53 (a 2, b 2)).

Similarly to Embodiment 1, the rotational force is transmitted to thecoupling 4150, the pin 155, the drum shaft 153, and the photosensitivedrum 107 through the drive shaft 180 from the motor 186. The urgingforce of the urging member 4159 act on the coupling 4150 at the time ofthe rotation. However, as has been described hereinbefore, the urgingforce of the urging member 4159 act to the coupling 4150 through thecontact member 4160. Therefore, the coupling 4150 can be rotated withouthigh load. In addition, the contact member 4160 may not be provided ifthe driving torque of the motor 186 is sufficiently large. In this case,even if the contact member 4160 is not provided, the coupling 4150 cantransmit the rotational force with high precision.

In addition, in the process in which the cartridge B is demounted fromthe apparatus main assembly A, the step opposite from the step to mountis followed. In other words, the coupling 4150 is normally urged to thedownstream with respect to the mounting direction X4 by the urgingmember 4159. Therefore, in the dismounting process of the cartridge B,the receiving surface 4150 f is in contact with the free end portion182A of the pin 182 in the upstream side with respect to the mountingdirection X4 (FIG. 53 (c 1)). In addition, a gap n50 is necessarilyprovided between the free end 180 b of the transmitting surface 4150 fand the drive shaft 180 in the downstream with respect to the mountingdirection X4. In the above-described embodiments, in the dismountingprocess of the cartridge, the receiving surface 150 f or the projection150 d in the downstream with respect to the mounting direction X4 of thecoupling has been described as contacting to the free end portion 180 bof the drive shaft 180 at least (for example, FIG. 25). However, as inthe present embodiment, the receiving surface 150 f or the projection4150 d in the downstream with respect to the mounting direction X4 ofthe coupling does not contact to the free end portion 180 b of the driveshaft 180, but corresponding to the dismounting operation of thecartridge B, the coupling 4150 can separate from the drive shaft 180.And, even after the coupling 4150 departs from the drive shaft 180, bythe urging force of the urging member 4159, the axis L2 inclines towardthe downstream with respect to the mounting direction X4 relative to theaxis L1 (disengaging angular position). More particularly, in thisembodiment, the angle of the pre-engagement angular position and theangle of the disengaging angular position relative to the axis L1 areequivalent relative to each other. This is because the coupling 4150 isurged by the elastic force of the spring.

In addition, the urging member 4159 has the function of inclining theaxis L2, and it further has the function of regulating the incliningdirection of the coupling 4150. More particularly, the urging member4159 functions also as the regulating means for regulating the incliningdirection of the coupling 4150.

As has been described hereinbefore, in this embodiment, the coupling4150 is urged by the elastic force of the urging member 4159 provided inthe bearing member 4157. By this, the axis L2 is inclined relative tothe axis L1. Therefore, the inclined state of the coupling 4150 ismaintained. Therefore, the coupling 4150 can be assuredly engaged withthe drive shaft 180.

The urging member 4159 described in this embodiment is provided in therib 4157 e of the bearing member 4157. However, the present embodimentis not limited to such an example. For example, it may be anotherportion of the bearing member 4157 and may be any member fixed to thecartridge B (other than the bearing member).

In addition, in this embodiment, the urging direction of the urgingmember 4159 is the direction of the axis L1. However, the urgingdirection may be any direction if the axis L2 inclines toward thedownstream with respect to the mounting direction X4 of the cartridge B.

In addition, in order to incline the coupling 4150 more assuredly towardthe downstream with respect to the mounting direction of the cartridgeB, a regulating portion for regulating the inclining direction of thecoupling may be provided in the process cartridge (FIG. 31).

In addition, in this embodiment, the energizing position of the urgingmember 4159 is at the flange portion 4150 j. However, the position ofthe coupling may be any if the axis L2 is inclined toward the downstreamwith respect to the mounting direction of the cartridge.

In addition, the present embodiment may be implemented in combinationwith Embodiment 4. In this case, the mounting and dismounting operationof the coupling can further be ensured.

[Embodiment 6]

Referring to FIG. 54-FIG. 58, the sixth embodiment of the presentinvention will be described.

In this embodiment, another means to maintain the state where the axisL1 is inclined relative to the axis L1 will be described.

FIG. 54 is an exploded perspective view of the process cartridge of thisembodiment. FIG. 55 is an enlarged side view of the driving side of thecartridge. FIG. 56 is a schematic longitudinal sectional view of thedrum shaft, the coupling, and the bearing member. FIG. 57 is alongitudinal sectional view which illustrates the operation which mountsthe coupling relative to the drive shaft. FIG. 58 is a sectional viewwhich illustrates a modified example of a coupling locking member.

As shown in FIG. 54 and FIG. 56, the drum bearing member 5157 isprovided with a coupling locking member 5157 k. At the time ofassembling the bearing member 5157 in the direction of the axis L1, apart of a locking surface 5157 k 1 of the locking member 5157 k engageswith the upper surface 5150 j 1 of a flange portion 5150 j, whilecontacting to the inclined surface 5150 m of the coupling 5150. At thistime, the flange portion 5150 j is supported with the play (angle α 49),in the rotational direction, between locking surface 5157 k 1 of thelocking portion 5157 k, and circular column portion of the drum shaft153 153 a. The following effects are provided by providing this play(angle α49). More particularly, even if the dimensions of the coupling5150, the bearing member 5157, and the drum shaft 153 vary within thelimits of the tolerance thereof, an upper surface 5150 j 1 can be lockedassuredly in a lock face 5157 k 1.

And, as shown in FIG. 56 (a), as for the axis L2, the driven portion5150 a side relative to the axis L1 inclines toward the downstream withrespect to the mounting direction (X4) of the cartridge. In addition,since the flange portion 5150 j exists over the full-circumference, itcan retain irrespective of the phase of the coupling 5150. Furthermore,as has been described with respect to Embodiment 1, the coupling 5150can be inclined only in the mounting direction X4 by the regulatingportion 5157 h 1 or 5157 h 2 (FIG. 55) as the regulating means. Inaddition, in this embodiment, the coupling locking member 5157 k isprovided in the downstreammost side with respect to the mountingdirection (X4) of the cartridge.

As will be described hereinafter, in the state where the coupling 5150is in engagement the drive shaft 180, the flange portion 5150 j isreleased from the locking member 5157 k as shown in FIG. 56 (b). And,the coupling 5150 is free from the locking member 5157 k. When it is notable to retain the state of inclining the coupling 5150 in the case ofthe assemblying of the bearing member 5157, the driven portion 5150 a ofthe coupling is pushed by tool and so on (FIG. 56 (b), arrow X14). Bydoing so, the coupling 5150 can be easily returned to the inclinedholding state (FIG. 56 (a)).

In addition, the rib 5157 m is provided in order to protect from theuser touching on the coupling easily. The rib 5157 m is set to thesubstantially same height as the free end position in the inclined stateof the coupling (FIG. 56 (a)). Referring to FIG. 57, the operation (apart of mounting operation of the cartridge) for engaging the coupling5150 with the drive shaft 180 will be described. In FIG. 57, (a)illustrates the state of the coupling immediately before engaging, (b)illustrates the state after a part of coupling 5150 passes the driveshaft 180, (c) illustrates the state where the inclination of thecoupling 5150 is released by the drive shaft 180, and (d) illustratesthe engaged state.

In the states of (a) and (b), the axis L2 of the coupling 5150 inclinestoward the mounting direction X4 relative to the axis L1 beforehand(pre-engagement angular position). By the coupling 5150 inclining, thefree end position 5150A1 is closer to the photosensitive drum than thefree end 180 b 3 in the direction of the axis L1. In addition, the freeend position 5150A2 is closer to the pin 182 than the free end 180 b 3.In addition, as has been described hereinbefore, at this time, theflange portion 5150 j is in contact with the locking surface 5157 k 1,and the inclined state of the coupling 5150 is maintained.

Thereafter, as shown in (c), the receiving surface 5150 f or theprojection 5150 d contacts to the free end portion 180 b or the pin 182by the cartridge B moving to the mounting direction X4. The flangeportion 5150 j separates from the locking surface 5157 k 1 by thecontact force thereof. And, the lock relative to the bearing member 5157of the coupling 5150 is released. And, in response to the cartridgemounting operation, the coupling is inclined so that the axis L2 thereofbecomes substantially co-axial with the axis L1. After the flangeportion 5150 j passes, the locking member 5157 k returns to the previousposition by restoring force. At this time, the coupling 5150 is freefrom the locking member 5157 k. And, finally, as shown in (d), the axisL1 and the axis L2 become substantially co-axial, and the rotationstand-by state is established (rotational force transmitting angularposition).

In addition, the step similar to Embodiment 1 is followed in the processin which the cartridge B is demounted from the apparatus main assembly A(FIG. 25). More particularly, the coupling 5150 is changed in the orderof (d), (c), (b), and (a) by the movement in the dismounting directionX6 of the cartridge. First, the free end portion 180 b pushes thereceiving surface 5150 f (the cartridge side contact portion). By this,the axis L2 inclines relative to the axis L1, and the lower surface 5150j 2 of the flange portion begins to contact to the inclined surface 5157k 2 of the locking member 5157 k. And, an elastic portion 5157 k 3 ofthe locking member 5157 k bends, and a locking surface free end 5157 k 4departs from the inclining locus of the flange portion 5150 j (FIG. 57(c)). Furthermore, the flange portion 5150 j and the locking surface5157 k 1 contact relative to each other as the cartridge advances in thedismounting direction (X6). By this, the inclination angle of thecoupling 5150 is maintained (FIG. 57 (b)). More particularly, thecoupling 5150 is swung (pivoted) from the rotational force transmittingangular position to the disengaging angular position.

As has been described hereinbefore, the angular position of the coupling5150 is maintained by the locking member 5157 k. By this, theinclination angle of the coupling is maintained. Therefore, the coupling5150 can be assuredly engaged with the drive shaft 180. Furthermore, atthe time of the rotation, the locking member 5157 k is not in contactwith the coupling 5150. Therefore, the stabilized rotation can beaccomplished by the coupling 5150.

The motion of the coupling shown in FIGS. 56, 57 and 58 may includewhirling motion.

In this embodiment, the locking member 5157 k is provided with anelastic portion. However, it may be the rib which does not have theelastic portion. More particularly, an amount of engagement between thelocking member 5157 k and the flange portion 5150 j is decreased. Bythis, the similar effect can be provided by making the flange portion5150 j deform to a slight degree (FIG. 58 (a)).

In addition, the locking member 5157 k is provided in the downstreammost side with respect to the mounting direction X4. However, if theinclination toward the predetermined direction of the axis L2 can bemaintained, the position of the locking member 5157 k may be any.

FIGS. 58 (b) and (c) illustrate the example in which the couplinglocking portion 5357 k (FIG. (58 b)) and 5457 k (FIG. 58c ) are providedin the upstream with respect to the mounting direction X4.

In addition, the locking member 5157 k has been constituted by a part ofbearing member 5157 in the above-described embodiment. However, if it isfixed to the cartridge B, the locking member 5157 k may be constitutedas a part of a member other than the bearing member. In addition, thelocking member may be a separate member.

In addition, the present embodiment may be implemented with Embodiment 4or Embodiment 5. In this case, the mounting and dismounting operationwith the more assured coupling is accomplished.

[Embodiment 7]

Referring to FIG. 59-FIG. 62, the seventh embodiment of the presentinvention will be described.

In this embodiment, another means for maintaining the axis of thecoupling at the inclined state relative to the axis of thephotosensitive drum will be described.

FIG. 59 is a perspective view which illustrates the state of pasting amagnet member (peculiar to the present embodiment) on the drum bearingmember. FIG. 60 is an exploded perspective view. FIG. 61 is an enlargedperspective view of a major part of the driving side of the cartridge.FIG. 62 is a perspective view and a longitudinal sectional view whichillustrate the drive shaft and an engaged state between the coupling.

As shown in FIG. 59, a drum bearing member 8157 constitutes a space 8157b which surrounds a part of coupling. A magnet member 8159 as amaintaining member for maintaining the inclination of the coupling 8150is pasted on a cylinder surface 8157 i which constitutes the spacethereof. In addition, as shown in FIG. 59, the magnet member 8159 isprovided in the upstream (with respect to the mounting direction X4) ofthe cylinder surface 8157 i. As will be described hereinafter, thismagnet member 8159 is a member for maintaining temporarily the statewhere the axis L2 inclines relative to the axis L1. Here, a part ofcoupling 8150 is made of magnetic material. And, the magnetic portion isattracted to the magnet member 8159 by a magnetic force of a magnetmember 8159. In this embodiment, the substantially full-circumference ofthe flange portion 8150 j is made of the metal magnetic material 8160.In other words, as shown in FIG. 61, the flange portion 8150 j contactsto this magnet member 8159 by the magnetic force. By this, the axis L2maintains the state of inclining toward the downstream with respect tothe mounting direction (X4) of the cartridge relative to the axis L1(FIG. 62 (a 1)). Similarly to Embodiment 1 (FIG. 31), an incliningdirection regulation rib 8157 h is preferably provided in the bearingmember 8157. The inclining direction of the coupling 8150 is moreassuredly determined by provision of the rib 8157 h. And, the flangeportion 8150 j of magnetic material and the magnet member 8159 cancontact to each other more assuredly. Referring to FIG. 60, thedescription will be made about the assembly method of the coupling 8150.

As shown in FIG. 60, the pin 155 enters a standing-by space 8150 g ofthe coupling 8150, and a part of coupling 8150 is inserted into a spaceportion 8157 b of the drum bearing member 8157. At this time,preferably, a distance D12 between an inner surface end of a retentionrib 8157 e of the bearing member 8157 and the magnet member 8159 islarger than the maximum outer diameter of a driven portion 8150 a ΦD10.In addition, the distance D12 is smaller than the maximum outer diameterof a driving portion 8150 b ΦD11. By this, the bearing member 8157 canbe assembled straight. Therefore, the assembling property improves.However, the present embodiment is not limited to this relation.

Referring to FIG. 62, the engaging operation (a part of mountingoperation of the cartridge) for engaging the coupling 8150 with thedrive shaft 180 will be described. FIGS. 62(a 1) and (b 1) illustratesthe state immediately before the engagement, and FIGS. 62 (a 2) and (b2) illustrate the state of the engagement completion.

As shown in FIGS. 62 (a 1) and (b 1), the axis L2 of the coupling 8150inclines toward the downstream with respect to the mounting direction X4relative to the axis L1 beforehand by the force of the magnet member(maintaining member) 8159 (pre-engagement angular position).

Thereafter, the free end surface 180 b or the pin 182 free end contactsto the driving shaft receiving surface 8150 f of the coupling 8150 bythe cartridge B moving to the mounting direction X4. And, the axis L2approaches so that it may become substantially co-axial with the axis L1by the contact force (mounting force of the cartridge) thereof. At thistime, the flange portion 8150 j separates from the magnet member 8159,and is in the non-contact state. And, finally, the axis L1 and the axisL2 become substantially co-axial. And, the coupling 8150 is in therotation latency state (FIG. 62 (a 2), Figure (b 2)) (rotational forcetransmitting angular position).

The motion shown in FIG. 62 may include whirling motion.

As has been described hereinbefore, in this embodiment, the inclinedstate of the axis L2 is maintained by the magnetic force of the magnetmember 8159 (maintaining member) pasted on the bearing member 8157. Bythis, the coupling can be more assuredly engaged with the drive shaft.

[Embodiment 8]

Referring to FIG. 63-FIG. 68, the eighth embodiment of the presentinvention will be described.

In this embodiment, another means to maintain the state where the axisL2 is inclined relative to the axis L1 will be described.

FIG. 63 is a perspective view which illustrates a driving side of acartridge. FIG. 64 is an exploded perspective view which illustrates astate before assembling a drum bearing member. FIG. 65 is a schematiclongitudinal sectional view of a drum shaft, a coupling, and a drumbearing member. FIG. 66 is a perspective view which illustrates adriving side of an apparatus main assembly guide. FIG. 67 is alongitudinal sectional view which illustrates disengagement of a lockmember. FIG. 68 is a longitudinal sectional view which illustrates theengaging operation of the coupling to the drive shaft.

As shown in FIG. 63, the coupling 6150 is inclined toward the downstreamwith respect to the mounting direction (X4) by the locking member 6159and the spring member 6158.

First, referring to FIG. 64, the description will be made about a drumbearing member 6157, a locking member 6159, and a spring member 6158.The bearing member 6157 is provided with an opening 6157 v. And, theopening 6157 v and the locking portion (locking member) 6159 a engagewith each other. By this, a free end 6159 a 1 of the locking portion6159 a projects into a space portion 6157 b of the bearing member 6157.As will be described hereinafter, the state of inclining the coupling6150 by this locking portion 6159 a is maintained. The locking member6159 is mounted to the space 6157 p of the bearing member 6157. Thespring member 6158 is mounted by the boss 6157 m of the hole 6159 b andthe bearing member 6157. The spring member 6158 in the presentembodiment employs a compression coil spring which has a spring force(elastic force) of about 50 g-300 g. However, if it is a spring whichproduces the predetermined spring force, any may be used. In addition,the locking member 6159 is the movable in the mounting direction X4 bythe engagement with the slot 6159 d and the rib 6157 k.

When the cartridge B is outside the apparatus main assembly A (statewhere the cartridge B is not mounted to the apparatus main assembly A),the coupling 6150 is in the state of inclining. In this state, a lockingportion free end 6159 a 1 of the locking member 6159 is in the movablerange T2 (hatching) of the flange portion 6150 j. FIG. 64 (a) shows anorientation of the coupling 6150. By this, the inclination orientationof the coupling can be maintained. Furthermore, the locking member 6159is abutted to an outer surface 6157 q (FIG. 64 (b)) of the bearingmember 6157 by the spring force of the spring member 6158. By this, thecoupling 6150 can maintain the stabilized orientation. In order toengage the coupling 6150 with the drive shaft 180, this lock is releasedto permit the inclination of the axis L2. In other words, as shown inFIG. 65 (b), the locking portion free end 6159 a 1 moves in thedirection of X12 to retract from the movable range T2 of the flangeportion 6150 j.

The description will further be made about the releasing of the lockingmember 6159.

As shown in FIG. 66, the main assembly guide 6130R1 is provided with thelock releasing member 6131. At the time of mounting the cartridge B tothe apparatus main assembly A, the releasing member 6131 and the lockingmember 6159 engage with each other. By this, the position of the lockingmember 6159 in the cartridge B changes. Therefore, the coupling 6150becomes pivotable.

Referring to FIG. 67, the releasing of the locking member 6159 will bedescribed. When the free end position 6150A1 of the coupling 6150 comesto the neighborhood of the shaft free-end 180 b 3 by the movement, inthe mounting direction X4, of the cartridge B, the releasing member 6131and the locking member 6159 engage with each other. At this time, a rib6131 a of the releasing member 6131 (contact portion) and a hook portion6159 c of the locking member 6159 (force receiving portion) contact toeach other. By this, the position of the locking member 6159 in theinside of the apparatus main assembly A is fixed (b). Thereafter, thelocking portion free end 6159 a 1 is located in the space portion 6157 bby the cartridge moving through 1-3 mm in the mounting direction.Therefore, the drive shaft 180 and the coupling 6150 are engageable witheach other, and the coupling 6150 is in the swingable (pivotable) state(c).

Referring to FIG. 68, the engaging operation of the coupling relative tothe drive shaft and the position of the locking member will bedescribed.

In the state of FIGS. 68 (a) and (b), the axis L2 of the coupling 6150inclines toward the mounting direction X4 relative to the axis L1beforehand (pre-engagement angular position). At this time, with respectto the direction of the axis L1, the free end position 6150A1 is closerto the photosensitive drum 107 than the shaft free-end 180 b 3 and, thefree end position 6150A2 is closer to the pin 182 than the shaftfree-end 180 b 3. In the state of (a), the locking member (forcereceiving portion) 6159 is engaged in the state for receiving the forcefrom the lock releasing member (contact portion) 6131. And, in the stateof (b), the locking portion free end 6159 a 1 retracts from the spaceportion 6157 b. By this, the coupling 6150 is released from theorientation maintenance state. More particularly, the coupling 6150becomes swingable (pivotable).

Thereafter, as shown in (c), by the movement of the cartridge toward themounting direction X4, driving shaft receiving surface 6150 f of thecoupling 6150 (the cartridge side contact portion) or projection 6150 dcontacts to the free end portion 180 b or the pin 182. And, in responseto the movement of the cartridge, the axis L2 approaches so that it maybecome substantially co-axial with the axis L1. And, finally, as shownin (d), the axis L1 and the axis L2 become substantially co-axial. Bythis, the coupling 6150 is in the rotation latency state (rotationalforce transmitting angular position).

The timing at which the locking member 6159 retracts is as follows. Moreparticularly, after the free end position 6150A1 passes by the shaftfree-end 180 b 3, and before the receiving surface 6150 f or theprojection 6150 d contacts to the free end portion 180 b or the pin 182,the locking member 6159 retracts. By doing so, the coupling 6150 doesnot receive an excessive load, and the assured mounting operation isaccomplished. The receiving surface 6150 f has a tapered shape.

In addition, in the dismounting process from the apparatus main assemblyA of the cartridge B, the step opposite from the step to mount isfollowed. More particularly, by moving the cartridge B in thedismounting direction, the free end portion 180 b of the drive shaft(the main assembly side engaging portion) 180 pushes the receivingsurface 6150 f (the cartridge side contact portion). By this, the axisL2 begins (FIG. 68 (c)) to incline relative to the axis L1. And, thecoupling 6150 passes by the shaft free-end 180 b 3 completely (FIG. 68(b)). The hook portion 6159 c spaces from the rib 6131 a immediatelyafter that. And, the locking portion free end 6159 a 1 contacts to thelower surface 6150 j 2 of the flange portion. Therefore, the inclinedstate of the coupling 6150 is maintained (FIG. 68 (a)). Moreparticularly, the coupling 6150 is pivoted to the disengaging angularposition from the rotational force transmitting angular position(swinging).

The motion shown in FIGS. 67 and 68 may include whirling motion.

As has been described hereinbefore, the inclination angle position ofthe coupling 6150 is maintained by the locking member 6159. By this, theinclined state of the coupling is maintained. Therefore, the coupling6150 is more assuredly mounted relative to the drive shaft 180.Furthermore, at the time of the rotation, the locking member 6159 doesnot contact to the coupling 6150. Therefore, the coupling 6150 caneffect more stabilized rotation.

In the embodiment described above, the locking member is provided in theupstream with respect to the mounting direction. However, the positionof the locking member may be any if the inclination in the predetermineddirection of the axis of the coupling is maintained.

In addition, the present embodiment may be implemented with Embodiments4-7. In this case, mounting and dismounting operations of the couplingcan be ensured.

[Embodiment 9]

Referring to FIG. 69-FIG. 73, the ninth embodiment of the presentinvention will be described.

In this embodiment, another means for inclining the axis L2 relative tothe axis L1 will be described.

FIG. 69 is an enlarged side view of a driving side of a cartridge. FIG.70 is a perspective view which illustrates a driving side of anapparatus main assembly guide. FIG. 71 is a side view which illustratesa relation between the cartridge and the main assembly guide. FIG. 72 isa side view and a perspective view which illustrate a relation betweenthe main assembly guide and the coupling. FIG. 73 is a side view whichillustrates a mounting process.

FIG. 69 (a 1) and FIG. 69 (b 1) are a side views of the cartridge (asseen from the drive shaft side), and FIG. 69 (a 2) and FIG. 69 (b 2) area side views of the drive shaft (as seen from the opposite side) of thecartridge. As shown in FIG. 69, in the pivotable state toward thedownstream with respect to the mounting direction (X4), the coupling7150 is mounted to the drum bearing member 7157. In addition, as for theinclining direction, as has been described with respect to Embodiment 1,it is pivotable only to the downstream with respect to the mountingdirection X4 by the retention rib (regulating means) 7157 e. Inaddition, in FIG. 69 (b 1), the axis L2 of the coupling 7150 inclineswith the angle α 60 relative to the horizontal line. The reason why thecoupling 7150 inclines with the angle α 60 is as follows. In the flangeportion 7150 j of the coupling 7150, a regulating portion 7157 h 1 or7157 h 2 as the regulating means regulate. Therefore, the downstreamside (mounting direction) of the coupling 7150 is pivotable toward thedirection upwardly inclined by the angle α 60.

Referring to FIG. 70, the description will be made about the mainassembly guide 7130R. The main assembly guide 7130R1 includes a guiderib 7130R1 a for guiding the cartridge B through the coupling 7150, andcartridge positioning portions 7130R1 e, 7130R1 f. The rib 7130R1 a ison the mounting locus of the cartridge B. And, the rib 7130R1 a isextended to just before the drive shaft 180 with respect to thecartridge mounting direction. And, the rib 7130R1 b adjacent to thedrive shaft 180 has the height to avoid interference When the coupling7150 engages with the drive shaft 180. The main assembly guide 7130R2mainly includes a guide portion 7130R2 a and the cartridge positioningportion 7130R2 c for determining the orientation at the time of themounting of the cartridge by guiding a part cartridge frames B1.

The relation between the main assembly guide 7130R and the cartridge atthe time of mounting the cartridge will be described.

As shown in FIG. 71 (a), in the driving side, while a connecting portion(force receiving portion) 7150 c of the coupling 7150 contacts to theguide rib (contact portion) 7130R1 a, a cartridge B moves. At this time,the cartridge guide 7157 a of the bearing member 7157 is separated fromthe guide surface 7130R1 c by n59. Therefore, the weight of thecartridge B is applied to the coupling 7150. In addition, on the otherhand, as has been described hereinbefore, the coupling 7150 is set, sothat it is pivotable toward the direction to which the downstream sidewith respect to the mounting direction upwardly inclines by the angleα60 relative to the mounting direction (X4). Therefore, the drivenportion 7150 a of the coupling 7150 inclines toward the downstream(direction inclined by the angle α 60 from the mounting direction) withrespect to the mounting direction X4 (FIG. 72).

The reason for the inclination of the coupling 7150 is as follows. Theconnecting portion 7150 c receives the reaction force corresponding tothe weight of the cartridge B from the guide rib 7130R1 a. And, thereaction force applies to the regulating portion 7157 h 1 or 7157 h 2for regulating the inclining direction. By this, the coupling isinclined to the predetermined direction.

Here, when the connecting portion 7150 c moves on the guide rib 7130R1a, a frictional force is between the connecting portion 7150 c and theguide rib 7130R1 a. Therefore, the coupling 7150 receives a force in thedirection opposite from the mounting direction X4 by this frictionalforce. However, the frictional force produced by the coefficient offriction between the connecting portion 7150 c and the guide rib 7130R1a is smaller than the force for pivoting the coupling 7150 to thedownstream with respect to the mounting direction X4 by the reactionforce. Therefore, the coupling 7150 overcomes the frictional force ispivoted to the downstream with respect to the mounting direction X4.

The regulating portion 7157 p (FIG. 69) of the bearing member 7157 maybe used as the regulating means for regulating the inclination. By this,the regulation of the inclining direction of the coupling is carried outat the different positions with respect to the direction of the axis L2by the regulating portions 7157 h 1, 7157 h 2 (FIG. 69) and theregulating portion 7157 p. By this, the direction which the coupling7150 inclines can be regulated more assuredly. In addition, it canalways be inclined toward the angle of approximately α 60. However, theregulation of the inclining direction of the coupling 7150 may be madeby another means.

In addition, the guide rib 7130R1 a is in the space 7150 s constitutedby the driven portion 7150 a, the driving portion 7150 b, and theconnecting portion 7150 c. Therefore, in the mounting process, thelongitudinal position (the direction of the axis L2) in the inside ofthe apparatus main assembly A of the coupling 7150 is regulated (FIG.71). By the longitudinal position of the coupling 7150 being regulated,the coupling 7150 can be more assuredly engaged relative to the driveshaft 180.

The engaging operation for engaging the coupling 7150 with the driveshaft 180 will be described. The engaging operation is the same as thatof Embodiment 1 substantially (FIG. 22). Here, referring to FIG. 73, thedescription will be made about the relation among the main assemblyguide main assembly guide 7130R2, the bearing member 7157, and thecoupling 7150 to the process which the coupling engages with the driveshaft 180. As long as the connecting portion 7150 c contacts to the rib7130R1 a, the cartridge guide 7157 a is separate from the guide surface7130R1 c. By this, the coupling 7150 is inclined (FIG. 73 (a), FIG. 73(d)) (pre-engagement angular position). At the time of the free end7150A1 of the inclined coupling 7150 passing by the shaft free-end 180 b3, the connecting portion 7150 c is departed from the guide rib 7130R1 a(FIG. 73 (b), FIG. 73 (e)). At this time, the cartridge guide 7157 apasses the guide surface 7130R1 c, and begins to contact to thepositioning surface 7130R1 e through the inclined surface 7130R1 d (FIG.73 (b), FIG. 73 (e)). After that, the receiving surface 7150 f or theprojection 7150 d contacts to the free end portion 180 b or the pin 182.And, in response to the cartridge mounting operation, the axis L2becomes substantially co-axial with the axis L1, and the center of thedrum shaft and the center of the coupling align with each other. And,finally, as shown in FIG. 73 (c) and FIG. 73 (f), the axis L1 and theaxis L2 are co-axial relative to each other. And, the coupling 7150 isin the rotation latency state (rotational force transmitting angularposition).

In addition, the step substantially opposite from the engaging operationis followed in the process which takes out the cartridge B from theapparatus main assembly A. In other words, the cartridge B moves in thedismounting direction. By this, the free end portion 180 b pushes thereceiving surface 7150 f. By this, the axis L2 begins to inclinerelative to the axis L1. The upstream free end portion 7150A1 withrespect to the dismounting direction moves on the shaft free-end 180 bby dismounting operation of the cartridge, and, the axis L2 inclinesuntil the upper free end portion A1 reaches the drive shaft free-end 180b 3. And, the coupling 7150 passes by the shaft free-end 180 b 3completely in this state (FIG. 73 (b)). After that, the connectingportion 7150 c contacts the coupling 7150 to the rib 7130R1 a. By this,the coupling 7150 is taken out in the state inclined toward thedownstream with respect to the mounting direction. In other words, thecoupling 5150 is pivoted to the disengaging angular position from therotational force transmitting angular position (swinging).

As has been described hereinbefore, the coupling swings by the usermounting the cartridge to the main assembly, and it engages with themain assembly driving shaft. In addition, a special means formaintaining the orientation of the coupling is unnecessary. However, theorientation maintenance structure as in the embodiment 4-embodiment 8may be used with the present embodiment.

In this embodiment, the coupling is inclined toward the mountingdirection by applying the weight to the guide rib. However, not only theweight, the spring force and so on may be utilized further.

In this embodiment, the coupling is inclined by the connecting portionof the coupling receiving the force. However, the present embodiment isnot limited to this example. For example, if the coupling is inclined byreceiving the force from a contact portion of the main assembly, theportion other than the connecting portion may be contacted to thecontact portion.

In addition, the present embodiment may be implemented with any of theembodiment 4-embodiment 8. In this case, the engagement anddisengagement relative to the drive shaft of the coupling can beensured.

[Embodiment 10]

Referring to FIG. 74-FIG. 81, the tenth embodiment of the presentinvention will be described.

In this embodiment, another means for inclining the axis L2 relative tothe axis L1 will be described.

FIG. 74 is a perspective view which illustrates a driving side of anapparatus main assembly.

Referring to FIG. 74, a main assembly guide and a coupling urging meanswill be described.

The present embodiment is effectively applied, in the case that thefrictional force described in Embodiment 9 would be larger than theforce of pivoting the coupling 7150 toward the downstream (mountingdirection X4) by the reaction force. More particularly, for example,even if the frictional force increases by rubbing action to theconnecting portion or the main assembly guide, the coupling can beassuredly pivoted to the pre-engagement angular position, according tothis embodiment. The main assembly guide 1130R1 includes. A guidesurface 1130R1 b for guiding the cartridge B through the cartridge guide140R1 (FIG. 2), A guide rib 1130R1 c which guides the coupling 150, andcartridge positioning portion 1130R1 a. The guide rib 1130R1 c is on themounting locus of the cartridge B. And, the guide rib 1130R1 c isextended to just before the drive shaft 180 with respect to thecartridge mounting direction. In addition, a rib 1130R1 d providedadjacent to the drive shaft 180 has a height not causing interferencewhen the coupling 150 engages.

A part of a rib 1130R1 c is cut away. And, the main assembly guideslider 1131 is mounted to the rib 1130R1 c slidably in the direction ofan arrow W. The slider 1131 is pressed by an elastic force of an urgingspring 1132. And, the position is determined by the slider 1131 abuttingto the abutment surface 1130R1 e of the main assembly guide 1130R1. Inthis state, the slider 1131 projects from the guide rib 1130R1 c.

The main assembly guide 1130R2 has a guide portion 1130R2 b fordetermining the orientation at the time of the mounting of the cartridgeB by guiding a part of cartridge frames B1, and a cartridge positioningportion 1130R2 a.

Referring to FIG. 75-FIG. 77, the among relation of the main assemblyguide 1130R1, 1130R2, the slider 1131, and the cartridge B, at the timeof mounting the cartridge B, will be described. FIG. 75 is a side view,as seen from the main assembly driving shaft 180 (FIGS. 1 and 2) side,and FIG. 76 is a perspective view thereof. FIG. 77 is a sectional viewtaken along Z-Z of FIG. 75.

As shown in FIG. 75, in the driving side, while the cartridge guide140R1 of the cartridge contacts to the guide surface 1130R1 b, thecartridge moves. At this time, as shown in FIG. 77, the connectingportion 150 c is separated from the guide rib 1130R1 c by n1. Therefore,the force is not applied to the coupling 150. In addition, as shown inFIG. 75, the coupling 150 is regulated by the regulating portion 140R1 aat the upper surface and the left side. Therefore, the coupling 150 isfreely pivotable only in the mounting direction (X4).

Referring to FIG. 78-FIG. 81, the operation of moving the slider 1131 tothe retreating position from the energizing position while the coupling150 contacts to the slider 1131, will be described. In FIG. 78-FIG. 79,the coupling 150 contacts in the apex 1131 b of the slider 1131, moreparticularly, the slider 1131 is in the retreating position. Theconnecting portion 150 c and the inclined surface of the projection ofthe slider 1131 1131 a contact with each other by the entrance of thecoupling 150 pivotable only in the mounting direction (X4). By this, theslider 1131 is depressed and it moves to the retreating position.

Referring to FIG. 80-FIG. 81, the operation after the coupling 150 ridesover an apex 1131 b of the slider 1131 will be described. FIG. 80-FIG.81 illustrate the state after the coupling 150 ride over the apex 1131 bof the slider 131.

When the coupling 150 rides over the apex 1131 b, the slider 1131 tendsto return from the retreating position to the energizing position by theelastic force of the urging spring 132. In that case, a part ofconnecting portion 150 c of the coupling 150 receives the force F fromthe inclined surface 1131 c of the slider 1131. More particularly, theinclined surface 1131 c functions as the force applying portion and itfunctions as the force receiving portion for a part of connectingportion 150 c to receive this force. As shown in FIG. 80, the forcereceiving portion is provided in the upstream of the connecting portion150 c with respect to the cartridge mounting direction. Therefore, thecoupling 150 can be inclined smoothly. As shown in FIG. 81, in addition,the force F is divided into a component force F1 and a component forceF2. At this time, the upper surface of the coupling 150 is regulated bythe regulating portion 140R1 a. Therefore, the coupling 150 is inclinedtoward the mounting direction (X4) by the component force F2. Moreparticularly, the coupling 150 is inclined toward the pre-engagementangular position. By this, the coupling 150 becomes engageable with thedrive shaft 180.

In the embodiment described above, the connecting portion receives theforce and the coupling is inclined. However, the present embodiment isnot limited to this example. For example, if the coupling is pivotableby receiving the force from the contact portion of the main assembly,the portion other than the connecting portion may contact with thecontact portion.

In addition, the present embodiment may be implemented with any of theembodiment 4-embodiment 9. In this case, the engagement anddisengagement of the coupling relative to the drive shaft can beensured.

[Embodiment 11]

Referring to FIG. 82-FIG. 84, the eleventh embodiment of the presentinvention will be described.

In the present embodiment, the configuration of the coupling will bedescribed. FIG. 82-FIG. 84 (a) are perspective views of couplings, FIG.82-FIG. 84 (b) are sectional views of the couplings.

In the previous embodiments, the driving shaft receiving surface and thedrum bearing surface of the coupling have conical shapes, respectively.However, in this embodiment, the different configuration will bedescribed.

A coupling 12150 shown in FIG. 82 mainly comprises three portionssimilarly to the coupling shown in FIG. 8. More particularly, as shownin FIG. 82 (b), the coupling 12150 comprises an a driven portion 12150 afor receiving the drive from the drive shaft, a driving portion 12150 bfor transmitting the drive to a drum shaft, and a connecting portion12150 c which connects the driven portion 12150 a and the drivingportion 12150 b with each other.

As shown in FIG. 82 (b), the driven portion 12150 a has a drive shaftinsertion opening portion 12150 m as an expanded part which expandstoward the drive shaft 180 relative to the axis L2 the driving portion12150 b has a drum shaft insertion opening portion 12150 v as anexpanded part which expands toward the drum shaft 153. An opening 12150m and an opening 12150 v are constituted by the driving shaft receivingsurface 12150 f of a divergent shape, and the drum bearing surface 12150i of a divergent shape, respectively. The receiving surface 12150 f andthe receiving surface 12150 i have the recesses 12150 x, 12150 z asshown in the Figure. At the time of the rotational force transmission,the recess 12150 z opposes to the free end of the drive shaft 180. Moreparticularly, the recess 12150 z covers the free end of the drive shaft180.

Referring to FIG. 83, a coupling 12250 will be described. As shown inFIG. 83 (b), a driven portion 12250 a has a drive shaft insertionopening portion 12250 m as an expanded part which expands toward thedrive shaft 180 relative to the axis L2 a driving portion 12250 b has adrum shaft insertion opening portion 12250 v as the expanded part whichexpands toward the drum shaft 153 relative to the axis L2.

An opening 12250 m and an opening 12250 v are constituted by the drivingshaft receiving surface 12250 f of a bell-like shape, and the drumbearing surface 12250 i of a bell-like shape, respectively. A receivingsurface 12250 f and a receiving surface 12250 i constitute the recesses12250 x, 12250 z as shown in the Figure. At the time of the rotationalforce transmission, the recess 12250 z engages with the free end portionof the drive shaft 180. Referring to FIG. 84, a coupling 12350 will bedescribed. As shown in FIG. 84 (a), a driven portion 12350 a includesdrive receiving projections 12350 d 1 or 12350 d 2 or 12350 d 3 and12350 d 4 which are directly extended from a connecting portion 12350 cand which expand radially toward the drive shaft 180 relative to theaxis L2. In addition, the portion between the adjacent projections 12350d 1-121350 d 4 constitutes the standing-by portion. Furthermore, therotational force receiving surfaces (rotational force receiving portion)12350 e (12350 e 1-e 4) are provided in the upstream with respect to therotational direction X7. At the time of the rotation, a rotational forceis transmitted to the rotational force receiving surfaces 12350 e 1-e 4from the pin (rotational force applying portion) 182. At the time of therotational force transmission, the recess 12250 z opposes to the freeend portion of the drive shaft which is the projection of the apparatusmain assembly. More particularly, the recess 12250 z covers the free endof the drive shaft 180.

In addition, if the effect similar to Embodiment 1 is provided, theconfiguration of the opening 12350 v may be any.

In addition, the mounting method to the cartridge of the coupling is thesame as that of Embodiment 1, and therefore, the description is omitted.In addition, the operation of mounting the cartridge to the apparatusmain assembly, and the operation of extracting from the apparatus mainassembly are the same as those of Embodiment 1 (FIGS. 22 and 25), andtherefore, the description is omitted.

As has been described hereinbefore, the drum bearing surface of thecoupling has the expanding configuration, and the coupling can bemounted relative to the axis of the drum shaft for inclination. Inaddition, the driving shaft receiving surface of the coupling has theexpanding configuration and can incline the coupling, withoutinterfering with the drive shaft in response to the mounting operationor the dismounting operation of the cartridge B. By this, also in thisembodiment, the effects similar to the first embodiment or the secondembodiment can be provided.

In addition, as for the configurations of the opening 12150 m, 12250 mand the opening 12150 v, 12250 v, they may be a combination of thedivergent, bell-like shapes.

[Embodiment 12]

Referring to FIG. 85, the twelfth embodiment of the present inventionwill be described.

The present embodiment is different from Embodiment 1 in theconfiguration of the coupling FIG. 85 (a) is a perspective view of acoupling which has a substantially cylindrical shape, and FIG. 85 (b) isa sectional view when the coupling mounted to the cartridge engages witha drive shaft.

A drive side edge of the coupling 9150 is provided with a plurality ofdriven projections 9150 d. In addition, a drive receiving stand-byportion 9150 k is provided between the drive receiving projections 9150d. The projection 9150 d is provided with a rotational force receivingsurface (rotational force receiving portion) 9150 e. A rotational forcetransmitting pin (rotational force applying portion) 9182 of the driveshaft 9180 as will be described hereinafter contacts to the rotationalforce receiving surface 9150 e. By this, a rotational force istransmitted to the coupling 9150.

In order to stabilize the running torque transmitted to the coupling, aplurality of rotational force receiving surfaces 150 e are desirablydisposed on the same circumference (on the phantom circle C1 of FIG. 8(d)). By the disposition in this manner, the rotational forcetransmission radius is constant and the torque transmitted isstabilized. In addition, from the viewpoint of the stabilization of thedrive transmission, the receiving surfaces 9150 e are desirably providedon the opposed positions (180 degrees) diametrically. In addition, thenumber of the receiving surfaces 9150 e may be any if the pin 9182 ofthe drive shaft 9180 can be received by the standing-by portion 9150 k.In the present embodiment, the number is two. The rotational forcereceiving surfaces 9150 e may not be on the same circumference, or theymay not be disposed diametrically opposed positions.

In addition, the cylinder surface of the coupling 9150 is provided withthe standby opening 9150 g. In addition, the opening 9150 g is providedwith the rotational force transmission surface (rotational forcetransmitting portion) 9150 h. The drive transmission pin (rotationalforce receiving member) 9155 (FIG. 85 (b)) of the drum shaft as will bedescribed hereinafter contacts to this rotational force transmissionsurface 9150 h. By this, the rotational force is transmitted to thephotosensitive drum 107.

Similarly to the projection 9150 d, the rotational force transmissionsurface 9150 h is desirably disposed diametrically opposed on the samecircumference.

The structures of the drum shaft 9153 and the drive shaft 9180 will bedescribed. In Embodiment 1, the cylindrical end is a spherical surface.In this embodiment, however, a diameter of a spherical free end portion9153 b of the drum shaft 9153 is larger than a diameter of a main part9153 a. With this structure, even if the coupling 9150 has thecylindrical shape as illustrated, it is pivotable relative to the axisL1. In other words, a gap g as illustrated is provided between the drumshaft 9153 and the coupling 9150 by this, the coupling 9150 is pivotable(swingable) relative to the drum shaft 9153. The configuration of thedrive shaft 9180 is the same as that of the drum shaft 9150substantially. In other words, the configuration of the free end portion9180 b is the spherical surface, and the diameter thereof is larger thanthe diameter of the main part 9180 a of the cylindrical shape portion.In addition, the pin 9182 which pierces through the substantial centerof the free end portion 9180 b which is the spherical surface isprovided the pin 9182 transmits the rotational force to the rotationalforce receiving surface 9150 e of the coupling 9150.

The drum shaft 9150 and the spherical surface of the drive shaft 9180are in engagement with the inner surface 9150 p of the coupling 9150. Bythis, the relative position between the drum shaft 9150 and the coupling9150 of the drive shaft 9180 is determined. The operation with respectto the mounting and demounting of the coupling 9150 is the same asEmbodiment 1, and therefore, the description thereof is omitted.

As has been described hereinbefore, the coupling has the cylindricalshape, and therefore, the position with respect to the directionperpendicular to the direction of the axis L2 of the coupling 9150 canbe determined relative to the drum shaft or the drive shaft. A modifiedexample of the coupling will be described further. In the configurationof the coupling 9250 shown in FIG. 85 (c), a cylindrical shape and aconical shape are put together. FIG. 85 (d) is a sectional view of thecoupling of this modified example. A driven portion 9250 a of thecoupling 9250 has a cylindrical shape, and an inner surface 9250 pthereof engages with the spherical surface of the drive shaft.Furthermore, it has the abutment surface 9250 q and can effect thepositioning with respect to the axial direction between the coupling9250 and the drive shaft 180. The driving portion 9250 b has a conicalshape, and, similarly to Embodiment 1, the position relative to the drumshaft 153 is determined by the drum bearing surface 9250 i.

The configuration of the coupling 9350 shown in FIG. 85 (e) is acombination of a cylindrical shape and a conical shape. FIG. 85 (f) is asectional view of this modified example the driven portion 9350 a of thecoupling 9350 has a cylindrical shape, and the inner surface 9350 pthereof engages with the spherical surface of the drive shaft 180. Thepositioning in the axial direction is effected by abutting the sphericalsurface of the drive shaft to the edge portion 9350 q formed between thecylindrical portions having different diameters.

The configuration of the coupling 9450 shown in FIG. 85 (g) is acombination of a spherical surface, a cylindrical shape, and a conicalshape. FIG. 85 (h) is a sectional view of this modified example a drivenportion 9450 a of the coupling 9450 has a cylindrical shape, and theinner surface 9450 p thereof engages with the spherical surface of thedrive shaft 180. A spherical surface of the drive shaft 180 is contactedto a spherical surface 9450 q which is a part of the spherical surface.By this, the position can be determined with respect to the direction ofthe axis L2.

In addition, in this embodiment, the coupling has the substantiallycylindrical shape and the free end portions of the drum shaft or thedrive shaft have the spherical configurations in addition, it has beendescribed that the diameter thereof is larger than the diameter of themain part of the drum shaft or the drive shaft. However, the presentembodiment is not limited to such an example. The coupling has acylindrical shape and the drum shaft or the drive shaft has acylindrical shape and, a diameter of the drum shaft or the drive shaftis small relative to an inner diameter of an inner surface of thecoupling within limits in which the pin does not disengage from thecoupling. By this, the coupling is pivotable relative to the axis L1 thecoupling can be inclined without interfering with the drive shaft inresponse to the mounting operation or the dismounting operation of thecartridge B. In view of this, also in this embodiment, the effectssimilar to Embodiment 1 or Embodiment 2 can be provided.

In addition, in this embodiment, although an example of the combinationof the cylindrical shape and conical shape has been described as theconfiguration of the coupling, it may be opposite to the example. Inother words, the drive shaft side may be formed into a conical shape,and the drum shaft side may be formed into a cylindrical shape.

[Embodiment 13]

Referring to FIG. 86-FIG. 88, the thirteenth embodiment of the presentinvention will be described.

The present embodiment is different from Embodiment 1 in the mountingoperation relative to the drive shaft of the coupling, and the structurewith respect to it. FIG. 86 is a perspective view which illustrates aconfiguration of a coupling 10150 of the present embodiment. Theconfiguration of the coupling 10150 is a combination of the cylindricalshape and conical shape which have been described in Embodiment 10. Inaddition, a tapered surface 10150 r is provided on the free end side ofa coupling 10150. In addition, the surface of an opposite side of thedrive receiving projection 10150 d with respect to the direction of theaxis L1 is provided with an urging force receiving surface 10150 s.

Referring to FIG. 87, the structure of the coupling will be described.

An inner surface 10150 p and a spherical surface 10153 b of a drum shaft10153 of the coupling 10150 are in engagement with each other. An urgingmember 10634 is interposed between a receiving surface 10150 s describedin the foregoing and a bottom surface 10151 b of a drum flange 10151. Bythis, the coupling 10150 is urged toward the drive shaft 180. Inaddition, similarly to the foregoing embodiments, a retention rib 10157e is provided in the drive shaft 180 side of the flange portion 10150 jwith respect to the direction of the axis L1. By this, the disengagementof the coupling 10150 from the cartridge is prevented the inner surface10150 p of the coupling 10150 is cylindrical. Therefore, it is themovable in the direction of the axis L2.

FIG. 88 is for illustrating the orientation of the coupling in the casethat the coupling engages with the drive shaft. FIG. 88 (a) is asectional view of the coupling 150 of Embodiment 1, and FIG. 88 (c) is asectional view of a coupling 10150 of the present embodiment. And, FIG.88 (b) is a sectional view before reaching the state of FIG. 88 (c) themounting direction is shown by X4 and the chain line L5 is a line drawnin parallel with the mounting direction from the free end of the driveshaft 180. In order for the coupling to engage with the drive shaft 180,the downstream free end position 10150A1 with respect to the mountingdirection needs to pass the free end portion 180 b 3 of the drive shaft180. In the case of Embodiment 1, the axis L2 inclines by more thanangle α104. By this, the coupling moves to the position where the freeend position 150A1 does not interfere with the free end portion 180 b 3(FIG. 88 (a)).

On the other hand, in the coupling 10150 of the present embodiment, itin the state where it does not be in engagement with the drive shaft180, the coupling 10150 takes the position nearest to the drive shaft180 by the restoring force of the urging member 10634. In this state,when it moves in the mounting direction X4, a part of drive shafts 180contact the cartridge B at the tapered surface 10150 r of the coupling10150 (FIG. 88 (b)). At this time, the force is applied to the taperedsurface 10150 r in the direction opposite the X4 direction therefore,the coupling 10150 is retracted in the longitudinal direction X11 by acomponent force thereof. And, the free end portion 10153 b of the drumshaft 10153 abuts to an abutting portion 10150 t of the coupling 10150in addition, the coupling 10150 rotates clockwisely about the center P1of the free end portion 10153 b (pre-engagement angular position). Bythis, the free end position 10150A1 of the coupling passes by the freeend 180 b of the drive shaft 180 (FIG. 88 (c)). When the drive shaft 180and the drum shaft 10153 becomes substantially co-axial, a driving shaftreceiving surface 10150 f of the coupling 10150 contacts to the free endportion 180 b by the restoring force of the urging spring 10634. Bythis, the coupling becomes in the rotation latency state (FIG. 87).(rotational force transmitting angular position). With such a structure,the movement in the direction of the axis L2 and the pivoting motion(swinging operation) are combined, and the coupling is swung from thepre-engagement angular position to the rotational force transmittingangular position.

By this structure, even if the angle α 106 (inclination amount of theaxis L2) is small, the cartridge can be mounted to the apparatus mainassembly A. Therefore, the space required by the pivoting motion of thecoupling 10150 is small. Therefore, latitude in the design of theapparatus main assembly A is improved.

The rotation according to the drive shaft 180 of the coupling 10150 isthe same as Embodiment 1, and therefore, the description thereof isomitted. At the time of taking out the cartridge B from the apparatusmain assembly A, the free end portion 180 b is forced on the conicalshape driving shaft receiving surface 10150 f of the coupling 10150 byremoving force. The coupling 10150 is pivoted by this force, whileretracting toward the direction of the axis L2 by this, the coupling isdemounted from the drive shaft 180. In other words, the moving operationin the direction of the axis L2 and the pivoting motion are combined(whirling motion may be includes), the coupling can be pivoted to thedisengaging angular position from the rotational force transmittingangular position.

[Embodiment 14]

Referring to FIG. 89-FIG. 90, the 14th embodiment of the presentinvention will be described.

The point in which the present embodiment is different from Embodiment 1is in the engaging operation and the structure with respect to itrelative to the drive shaft of the coupling.

FIG. 89 is a perspective view which illustrates only the coupling 21150and the drum shaft 153 FIG. 90 is a longitudinal sectional view, as seenfrom the lower of the apparatus main assembly As shown in FIG. 89, themagnet member 21100 is mounted to the end of the driving portion 21150 aof the coupling 21150 The drive shaft 180 shown in FIG. 90 comprisesmagnetic material Therefore, in this embodiment, the magnet member 21100is inclined in the coupling 21150 by the magnetic force between thedrive shaft 180 of it and magnetic material.

First, as shown in FIG. 90 (a), the coupling 21150 is not particularlyinclined relative to the drum shaft 153 at this time, the magnet member21100 is positioned in the driving portion 21150 a in the upstream withrespect to the mounting direction X4.

When it is inserted to the position shown in FIG. 90 (b), the magnetmember 21100 is attracted toward the drive shaft 180. And, asillustrated, the coupling 21150 begins the swinging motion by themagnetic force thereof.

Thereafter, the leading end position 21150A1 of the coupling 21150 withrespect to the mounting direction (X4) passes by the drive shaftfree-end 180 b 3 which has the spherical surface And, the driving shaftreceiving surface 21150 f of a conical shape or the driven projection21150 d (the cartridge side contact portion) which constitutes therecess 21150 z of the coupling 21150 contacts the free end portion 180 bor 182 after the passage (FIG. 90 (c)).

And, it inclines so that the axis L2 becomes substantially co-axial withthe axis L1 in response to the mounting operation of the cartridge B(FIG. 90 (d)).

Finally, the axis L1 and the axis L2 become substantially co-axial witheach other In this state, the recess 21150 z covers the free end portion180 b The axis L2 pivots the coupling 21150 to the rotational forcetransmitting angular position from the pre-engagement angular positionso that it is substantially co-axial with the axis L1 The coupling 21150and the drive shaft 180 are engaged with each other (FIG. 90 (e)).

Motion of the coupling shown in FIG. 90 may also include the revolution.

It is necessary to position the magnet member 21100 in the upstream ofthe driving portion 21150 a with respect to the mounting direction X4.

Therefore, at the time of mounting the cartridge B to the apparatus mainassembly A, it is necessary to align the phase of the coupling 21150 Themethod described with respect to Embodiment 2 is usable for the methodof doubling the phase of the coupling.

The state of receiving rotation driving force and rotating after themounting completion is the same as Embodiment 1 and therefore, thedescription is omitted.

[Embodiment 15]

Referring to FIG. 91, the 15th embodiment of the present invention willbe described.

The point in which the present embodiment is different from Embodiment 1is the manner of support of the coupling. In embodiment 1, the axis L2of the coupling thereof is pivotable, while being interposed between thefree end portion of the drum shaft and the retention rib. On the otherhand, in the present embodiment, the axis L2 of the coupling ispivotable only by the drum bearing member this will be described in moredetail.

FIG. 91 (a) is a perspective view which illustrates the state in thecourse of mounting the coupling. FIG. 91 (b) is a longitudinal sectionalview thereof. FIG. 91 (c) is a perspective view which illustrates thestate where the axis L2 inclines relative to the axis L1. FIG. 91 (d) isa longitudinal sectional view thereof. FIG. 91 (e) is a perspective viewwhich illustrates the state where the coupling rotates. FIG. 91 (f) is alongitudinal sectional view thereof.

In this embodiment, the drum shaft 153 is place(d) in a space defend byan inner surface of a space portion 11157 b of a drum bearing member11157 in addition, the rib 11157 e and the rib 11157 p are provided onthe inner surface opposite from the drum shaft 153 (at the differentpositions with respect to the direction of the axis L1).

With this structure, a flange portion 11150 j and a drum bearing surface11150 i are regulated by an inner end surface 11157 p 1 and circularcolumn portion 11153 a of the rib in the state in which the axis L2 isinclined (FIG. 91 (d)). Here, the end surface 11157 p 1 is provided inthe bearing member 11157. In addition, the circular column portion 11153a is a part of drum shaft 11153. And, when the axis L2 becomessubstantially co-axial with the axis L1 (FIG. 91 (f)), the flangeportion 11150 j and the taper outer surface 11150 q are regulated by theouter end 11157 p 2 of the rib 11157 e and the rib of the bearing member11157.

Therefore, the coupling 11150 is retained in the bearing member 11157 byselecting the configuration of the bearing member 11157 to theappropriate in addition, the coupling 11150 can be pivotably mountedrelative to the axis L1.

In addition, the drum shaft 11153 has only the drive transmittingportion in the free end thereof and, the spherical surface portion forregulating the movement of the coupling 11150 and so on is unnecessarytherefore, the processing of the drum shaft 11153 is easy.

In addition, the rib 11157 e and the rib 11157 p are disposed offset. Bythis, as shown in FIG. 91 (a) and FIG. 91 (b), the coupling 11150 isassembled into the bearing member 11157 in a slightly oblique direction(in the Figure X12) more particularly, the special method of assemblyingis unnecessary thereafter, the bearing member 11157 to which thecoupling 11150 was mounted temporarily is assembled into the drum shaft11153 (in the Figure the X13 direction).

[Embodiment 16]

Referring to FIG. 92, the 16th embodiment of the present invention willbe described.

The point of difference of the present embodiment from Embodiment 1 isin the mounting method of the coupling. In Embodiment 1, the coupling isinterposed between the free end portion and the retention rib of thedrum shaft. On the contrary, in this embodiment, the retention of thecoupling is effected by a rotational force transmitting pin (rotationalforce receiving member) 13155 of a drum shaft 13153. More particularly,in this embodiment, a coupling 13150 is held by a pin 13155.

This will be described in more detail.

FIG. 92 illustrates the coupling held at the end of the photosensitivedrum 107 (cylindrical drum 107 a) a part of driving side of thephotosensitive drum 107 is shown, and the others are omitted forsimplicity.

In FIG. 92 (a), the axis L2 is substantially co-axial relative to theaxis L1 in this state, a coupling 13150 receives a rotational force froma drive shaft 180 at a driven portion 13150 a. And, the coupling 13150transmits the rotational force to the photosensitive drum 107.

And, as shown in FIG. 92 (b), the coupling 13150 is mounted to a drumshaft 13153 so that it is pivotable in any direction relative to theaxis L1.

The configuration of the driven portion 13150 a may be the same as theconfiguration of the driven portion described with respect to FIG.82-FIG. 85 and, this photosensitive drum unit U13 is assembled into thesecond frame in the manner described with respect to Embodiment 1. And,at the time of mounting and demounting the cartridge B relative to theapparatus main assembly A, the coupling is engageable and detachablerelative to the drive shaft.

The mounting method according to the present embodiment will bedescribed. The free end (unshown) of the drum shaft 13153 is covered bythe coupling 13150 thereafter, the pin (rotational force receivingmember) 13155 is inserted into a hole (unshown) of the drum shaft 13153in the direction perpendicular to the axis L1. In addition, the oppositeends of the pin 13155 outwardly project beyond an internal surface of aflange portion 13150 j. The pin 13155 is prevented from separating fromthe standby opening 13150 g by these settings. By this, it is notnecessary to add a part for preventing the disengagement of the coupling13150.

As mentioned above, according to the embodiment described above, thedrum unit U13 is constituted by the cylindrical drum 107 a, the coupling13150, the photosensitive drum 107, the drum flange 13151, the drumshaft 13153, the drive transmission pin 13155, and so on. However, thestructure of the drum unit U13 is not limited to this example.

As means for inclining the axis L2 to the pre-engagement angularposition, immediately before the coupling engages with the drive shaft,the embodiment 3-embodiment 10 described until now can be employed.

In addition, with respect to engagement and disengagement between thecoupling and the drive shaft operated interrelatedly with the mountingand the dismounting of the cartridge, it is the same as that ofEmbodiment 1, and therefore, the description is omitted.

In addition, as has been described with respect to Embodiment 1 (FIG.31), the inclining direction of the coupling is regulated by the bearingmember. By this, the coupling can be more assuredly engaged with thedrive shaft.

With the above-described structures, the coupling 13150 is a part of thephotosensitive drum unit integral with the photosensitive drum.Therefore, at the time of the assembling, handling is easy, andtherefore, the assembling property can be improved.

[Embodiment 17]

Referring to FIG. 93, the 17th embodiment of the present invention willbe described.

The point that the present embodiment is different from Embodiment 1 isin the mounting method of the coupling. With respect to Embodiment 1,the coupling is mounted to the free end side of the drum shaft, so that,the axis L2 is slantable in any direction relative to axis L1. On thecontrary, in this embodiment, the coupling 15150 is directly mounted tothe end of the cylindrical drum 107 a of the photosensitive drum 107, sothat it is slantable in any direction.

This will be described in more detail.

FIG. 93 shows an electrophotographic photosensitive member drum unit(“drum unit”) U. A coupling 15150 is mounted to an end part of thephotosensitive drum 107 (cylindrical drum 107 a) in this Figure. As forthe photosensitive drum 107, a part of driving side is shown and theothers are omitted for the simplification.

The axis L2 is substantially co-axial relative to the axis L1 in FIG. 93(a). In this state, the coupling 15150 receives a rotational force fromthe drive shaft 180 at a driven portion 15150 a. And, the coupling 15150transmits the received rotational force to the photosensitive drum 107.

And, an example is shown in FIG. 93 (b), wherein the coupling 15150 ismounted to the end part of the cylindrical drum 107 a of thephotosensitive drum 107, so that it is slantable in any direction. Inthis embodiment, one end of the coupling is mounted not to the drumshaft (projection) but into the recess (rotational force receivingmember) provided at the end part of the cylinder 107 a. And, thecoupling 15150 is pivotable also in any direction relative to the axisL1. As for the driven portion 15150 a, the configuration described withrespect to Embodiment 1 is shown, but it may be a configuration of thedriven portion of the coupling described in Embodiment 10 or Embodiment11. And, as has been described with respect to Embodiment 1, this drumunit U is assembled into the second frame 118 (drum frame), and it isconstituted as the detachably mountable cartridge to the apparatus mainassembly.

Thus, the drum unit U is constituted by the coupling 15150, thephotosensitive drum 107 (cylindrical drum 107 a), the drum flange 15151,and so on.

As for a structure for inclining the axis L2 toward the pre-engagementangular position, immediately before the coupling 15150 engages with thedrive shaft 180, any of embodiment 3-embodiment 9 is usable.

In addition, the engagement and disengagement between the coupling andthe drive shaft which are operated interrelatedly with the mounting andthe dismounting of the cartridge are the same as those of Embodiment 1.Therefore, the description is omitted.

In addition, as has been described with respect to Embodiment 1 (FIG.31), the drum bearing member is provided with regulating means forregulating inclining direction of the coupling relative to axis L1. Bythis, the coupling can be more assuredly engaged with the drive shaft.

With this structure, the coupling can be slantably mounted without thedrum shaft which was described heretofore in any direction relative tothe photosensitive drum. Therefore, the cost reduction can beaccomplished.

In addition, according to the above structure, the coupling 15150 is apart of the drum units comprising the photosensitive drum as a unit.Therefore, in the cartridge, handling is easy at the time of theassembling, and the assembling property is improved.

Referring to FIG. 94-FIG. 105, the present embodiment will further bedescribed.

FIG. 94 is a perspective view of the process cartridge B-2 which usesthe coupling 15150 of the present embodiment. The outer periphery 15157a of an outside end of a drum bearing member 15157 provided at thedriving side functions as a cartridge guide 140R1.

In addition, in the one longitudinal end (driving side) of the secondframe unit 120, a cartridge guide 140R2 which outwardly projects isprovided substantially above a cartridge guide 140R1 which outwardlyprojects.

The process cartridge is supported detachably in the apparatus mainassembly by these cartridge guides 140R1, 1402 and a cartridge guide(unshown) provided at the non-driving side. More particularly, thecartridge B is moved to the apparatus main assembly A in the directionsubstantially perpendicular to the direction of the axis L3 of the driveshaft 180, when it is mounted to the apparatus main assembly A2 or isdemounted from it.

FIG. 95 (a) is a perspective view of the coupling, as seen from thedriving side, FIG. 95 (b) is a perspective view of the coupling, as seenfrom the photosensitive drum side, and FIG. 95 (c) shows a view of thecoupling, as seen from the direction perpendicular to the axis L2. FIG.95 (d) is a side view of the coupling, as seen from the driving side,FIG. 95 (e) shows a view, as seen from the photosensitive drum side, andFIG. 95 (f) is a sectional view taken along S21-S21 of FIG. 95 (d).

The coupling 15150 is engaged with the drive shaft 180 in the statewhere the cartridge B is mounted to the set portion 130 a provided inthe apparatus main assembly A. And, by removing the cartridge B from theset portion 103 a, it is disengaged from the drive shaft 180. And, inthe state where it engaged with the drive shaft 180, the coupling 15150receives the rotational force from the motor 186, and transmits arotational force to the photosensitive drum 107.

The coupling 15150 mainly comprises three portions (FIG. 95 (c)). Afirst portion is a driven portion (a portion to be driven) 15150 a whichhas a rotational force reception surface (rotational force receivingportion) 15150 e (15150 e 1-15150 e 4) for engaging with a drive shaft180 and receiving a rotational force from a pin 182. A second portion isa driving portion 15150 b which engages with a drum flange 15151 (pin15155 (rotational force receiving member)), and transmits a rotationalforce. A third portion is a connecting portion 15150 c which connectsthe driven portion 15150 a and the driving portion 15150 b. Thematerials of these portions are resin materials, such as polyacetal, thepolycarbonate, and PPS. However, in order to enhance rigidity of themember, the glass fiber, the carbon fiber, and so on may be mixed in theresin material depending on the required load torque. In addition, therigidity may further be enhance(d) by inserting metal in the abovedescribed resin material, and the whole coupling may be made with themetal and so on. The driven portion 15150 a is provided with a driveshaft insertion opening portion 15150 m in the form of an expanded partwhich expands into a conical shape relative to the axis L2 as shown inFIG. 95 (f). The opening 15150 m constitutes a recess 15150 z as shownin the Figure. The driving portion 15150 b has a spherical driving shaftreceiving surface 15150 i. The coupling 15150 can pivot between therotational force transmitting angular position and the pre-engagementangular position (disengaging angular position) relative to the axis L1by the receiving surface 15150 i. By this, the coupling 15150 is engagedwith the drive shaft 180 without being prevented by the free end portion180 b of the drive shaft 180 irrespective of the rotation phase of thephotosensitive drum 107. The driving portion 15150 b has the convexconfiguration as shown in the Figure.

And, a plurality of drive receiving projections 15150 d 1-d 4 areprovided on a circumference (phantom circle in FIG. 8 (d) C1) of an endsurface of the driven portion 15150 a. In addition, the spaces betweenthe adjacent projections 15150 d 1 or 15150 d 2 or 15150 d 3 and 15150 d4 function as drive receiving stand-by portions 15150 k 1, 15150 k 2,15150 k 3, 15150 k 4. Each interval between the adjacent projections15150 d 1-d 4 are larger than the outer diameter of the pin 182, so thatthe pin (rotational force applying portion) 182 is received theseintervals are standing-by portions 15150 k 1-k 4. In addition, in FIG.95 (d), in the clockwise downstream of the projection 15150 d, therotational force receiving surfaces (rotational force receiving portion)15150 e 1-15150 e 4 facing faced in the direction crossing with thedirection of the rotational movement of the coupling 15150 is provided.When the drive shaft 180 rotates, the pin 182 abuts or contacts to oneof the drive force receiving surfaces 15150 e 1-15150 e 4. And, thedrive force receiving facing 15150 is pushed by the side surface of thepin 182, and rotates the coupling 15150 about the axis L2.

In addition, the driving portion 15150 b has a spherical surface. Thecoupling 15150 can be pivoted between the rotational force transmittingangular position and the pre-engagement angular position (or disengagingangular position) by the provision of the spherical surface irrespectiveof the rotation phase of the photosensitive drum 107 in the cartridge B(swinging). In the illustrated example, spherical surface is a sphericaldrum bearing surface 15150 i which has its axis aligned with the axisL2. And, a hole 15150 g for penetration anchoring for the pin(rotational force transmitting portion) 15155 is formed through thecenter thereof.

Referring to FIG. 96, the description will be made as to an example of adrum flange 15151 which mounts the coupling 15150. FIG. 96 (a) shows aview as seen from the drive shaft side, and FIG. 96 (b) is a sectionalview taken along S22-S22 of FIG. 96 (a).

The openings 15151 g 1, 15151 g 2 shown in FIG. 96 (a) are in the formof grooves extended in the circumferential direction of the flange15151. An opening 15151 g 3 is provided between the opening 15151 g 1and the opening 15151 g 2. At the time of mounting the coupling 15150 tothe flange 15151, the pin 15155 is accommodated in these openings 15151g 1, 15151 g 2. In addition, the drum bearing surface 15150 i isaccommodated in the opening 15151 g 3.

With the above-described structures, irrespective of the rotation phaseof the photosensitive drum 107 (irrespective of the stop position of thepin 15155) in the cartridge B-2, the coupling 15150 is pivotable(swingable) between the rotational force transmitting angular positionand the pre-engagement angular positions (or disengaging angularposition).

In addition, in FIG. 96 (a), the rotational force transmission surfaces(rotational force receiving members) 15151 h 1, 15151 h 2 are providedin the clockwise upstream of the openings 15151 g 1 or 15151 g 2. And,the side surfaces of the rotational force transmitting pin (rotationalforce transmitting portion) 15155 of the coupling 15150 contact to therotational force transmission surfaces 15151 h 1, 15151 h 2. By this, arotational force is transmitted from the coupling 15150 to thephotosensitive drum 107. Here, the transmitting surfaces 15151 h 1-15151h 2 are faced in the circumferential direction of the rotationalmovement of the flange 15151. By this, the transmitting surfaces 15151 h1-15151 h 2 are pushed to the side surfaces of the pin 15155. And, inthe state of the axis L1 and the axis L2 being substantially co-axial,the coupling 15150 rotates about the axis L2.

Here, the flange 15151 has a transmission receiving portion 15151 h 1,15151 h 2, and therefore, it functions as a rotational force receivingmember.

The retaining portion 15151 i shown in FIG. 96 (b) has the function ofretaining the coupling 15150 to the flange 15151, so that the couplingcan pivot between the rotational force transmitting angular position andthe pre-engagement angular positions (or disengaging angular position)in addition, it has the function of regulating the movement of thecoupling 15150 in the direction of the axis L2. Therefore, the opening15151 j has diameter ΦD15 smaller than the diameter of the bearingsurface 15150 i. Thus, the motion of the coupling is limited by theflange 15151. Because of this, the coupling 15150 des not disengage fromthe photosensitive drum (cartridge).

As has been shown in FIG. 96, the driving portion 15150 b of thecoupling 15150 is in engagement with the recess provided in the flange15151.

FIG. 96 (c) is a sectional view which illustrates the process in whichthe coupling 15150 is assembled to the flange 15151.

The driven portion 15150 a and the connecting portion 15150 c areinserted in the direction X33 into the flange 15151. In addition, thepositioning member 15150 p (driving portion 15150 b) which has thebearing surface 15150 i is put in the direction of an arrow X32. The pin15155 penetrates a fixing hole 15150 g of the positioning member 15150p, and the fixing hole 15150 r of the connecting portion 15150 c. Bythis, the positioning member 15150 p is fixed to the connecting portion15150 c.

FIG. 96 (d) shows a sectional view which illustrates the process inwhich the coupling 15150 is fixed to the flange 15151.

The coupling 15150 is moved in the X32 direction, so that the bearingsurface 15150 i is brought into contact or proximity with the retainingportion 15151 i. The retaining portion material 15156 is inserted in thedirection of the arrow X32, and it is fixed to the flange 15151. Thecoupling 15150 is mounted to the flange 15151 with a play (gap) to thepositioning member 15150 p in this mounting method. By this, thecoupling 15150 can change the direction thereof.

Similarly to the projection 15150 d, the rotational force transmissionsurfaces 15150 h 1, 15150 h 2 are desirably disposed diametricallyopposed (180 degrees) on the same circumference.

Referring to FIG. 97 and FIG. 98, the structure of a photosensitive drumunit U3 will be described. FIG. 97 (a) is a perspective view of the drumunit, as seen from the driving side, and FIG. 97 (b) is a perspectiveview, as seen from the non-driving side. In addition, FIG. 98 is asectional view taken along S23-S23 of FIG. 97 (a).

A drum flange 15151 mounted to the coupling 15150 is fixed to one endside of the photosensitive drum 107 (cylindrical drum 107 a), so that atransmission part 15150 a is exposed. In addition, the drum flange 152of the non-driving side is fixed to the other end side of thephotosensitive drum 107 (cylindrical drum 107 a). This fixing method iscrimping, bonding, welding, or the like.

And, in the state where the driving side is supported by the bearingmember 15157 and the non-driving side is supported by the drumsupporting pin (unshown), the drum unit U3 is rotatably supported by thesecond frame 118. And, it is unified into the process cartridge bymounting the first frame unit 119 to the second frame unit 120 (FIG.94).

Designated by 15151 c is a gear, and has a function of transmitting arotational force received by the coupling 15150 from the drive shaft 180to the developing roller 110. The gear 15151 c is integrally molded withthe flange 15151.

The drum unit U3 described in this embodiment comprises the coupling15150, the photosensitive drum 107 (cylindrical drum 107 a), and thedrum flange 15151. The peripheral surface of the cylindrical drum 107 ais coated with a photosensitive layer 107 b. In addition, the drum unitcomprises the photosensitive drum coated with the photosensitive layer107 b, and the coupling mounted to one end thereof. The structure of thecoupling is not limited to the structure described in this embodiment.For example, it may have the structure described hereinbefore as theembodiments of the coupling. In addition, it may be another structure ifit has the structure in which the effects of the present invention areprovided.

Here, as shown in FIG. 100, the coupling 15150 is mounted so that it canincline in any direction relative to the axis L1 of the axis L2 thereof.FIGS. 100(a 1)-(a 5) are views as seen from the drive shaft 180, andFIGS. 100(b 1)-(b 5) are perspective views thereof. FIGS. 100(b 1)-(b 5)is partly broken views of substantially the entirety of the coupling15150, wherein a part of a flange 15151 is cut away for betterillustration.

In FIGS. 100 (a 1) (b 1), the axis L2 is co-axially positioned relativeto the axis L1. When the coupling 15150 is inclined upward from thisstate It is in the state shown in FIGS. 100 (a 2) (b 2). As shown inthis Figure, when the coupling 15150 inclines toward an opening 15151 gA pin 15155 is moved along the opening 15151 g. As a result, thecoupling 15150 is inclined about the axis AX perpendicular to theopening 15151 g.

The coupling 15150 is inclined rightward in FIG. 100 (a 3) (b 3). Asshown in this Figure, when the coupling 15150 inclines in the orthogonaldirection of the opening 15151 g, it rotates in the opening 15151 g. Thepin 15155 rotates about the axis line AY of the pin 15155.

The state where the coupling 15150 is inclined leftward and the statewhere it is inclined downward are shown in FIGS. 100 (a 4) (b 4) and 100(a 5) (b 5). Since the description of the rotation axis AX, AY has beenmade in the foregoing, the description therefor is omitted forsimplicity.

the rotation in the direction different from these inclining directions,for example, 45-degree rotation shown in FIG. 100 (a 1), is provided bya combination of the rotations around the rotation axes AX, AY. In thismanner, the axis L2 can be inclined in any directions relative to theaxis L1.

The opening 15151 g is extended in the direction crossing with theprojection direction of the pin 15155.

In addition, between the flange (rotational force receiving member)15151 and the coupling 15150, a gap is provided as shown in the Figure.With this structure, as has been described hereinbefore, the coupling15150 is pivotable in all the directions.

More particularly, the transmitting surfaces (rotational forcetransmitting portions) 15151 h (15151 h 1, 15151 h 2) are in theoperative positions relative to the pins 15155 (the rotational forcetransmitting portion). The pin 15155 is movable relative to thetransmitting surface 15151 h. The transmitting surface 15151 h and thepin 15155 are engaged or abutted to each other. To accomplish thismotion, a gap is provided between the pin 15155 and the transmittingsurface 15155 h. By this, the coupling 15150 is pivotable relative tothe axis L1 in all directions. In this manner, the coupling 15150 ismounted to the end of the photosensitive drum 107.

The axis L2 has been mentioned as being pivotable in any directionrelative to the axis L1. However, the coupling 15150 does notnecessarily need to be linearly pivotable to the predetermined angleover the 360-degree range. This is applied to all the couplingsdescribed as the embodiments in the foregoing.

In this embodiment, the opening 15151 g is formed slightly overwidely inthe circumferential direction. With this structure, when the axis L2inclines relative to the axis L1, even if it is the case where it cannotincline to the predetermined angle linearly, the coupling 15150 canincline to the predetermined angle by rotating to a slight degree aboutthe axis L2 in other words, the play of the opening 15151 g in therotational direction is selected properly in view of this, if necessary.

In this manner, the coupling 15150 is pivotable in all the directionssubstantially. Therefore, the coupling 15150 is revolvable (pivotable)over the full-circumference substantially relative to the flange 15151.

As has been described hereinbefore, (FIG. 98), the spherical surface15150 i of the coupling 15150 contacts to the retaining portion (a partof recess) 15151 i. Therefore, the center P2 of the spherical surface15150 i aligns with the rotation axis, and the coupling 15150 ismounted. More particularly, the axis L2 of the coupling 15150 ispivotable irrespective of the phase of the flange 15151.

In addition, in order for the coupling 15150 to engage with the driveshaft 180, the axis L2 is inclined toward the downstream with respect tothe mounting direction of the cartridge B-2 relative to the axis L1 justbefore the engagement. More particularly, as shown in FIG. 101, the axisL2 is inclined relative to the axis L1, so that the driven portion 15150a is the downstream with respect to the mounting direction X4. In FIGS.101 (a)-(c), the position of the driven portion 15150 a is downstreamwith respect to the mounting direction X4, in any case.

FIG. 94 illustrates the state where the axis L2 is inclined relative tothe axis L1. In addition, FIG. 98 is a sectional view taken alongS24-S24 of FIG. 94. As shown in FIG. 99, by the structure describedheretofore, from the state of the axis L2 being inclined, it can changeto the state of being substantially parallel to the axis L1. Inaddition, the maximum possible inclination angle α4 (FIG. 99) betweenthe axis L1 and the axis L2 is the angle at the time of inclining untilthe driven portion 15150 a or the connecting portion 15150 c contactswith the flange 15151 or the bearing member 15157. This inclinationangle is the value required for engagement and disengagement relative tothe drive shaft of the coupling at the time of mounting and demountingthe cartridge relative to the apparatus main assembly.

Immediately before or simultaneously with the cartridge B being set atthe predetermined position of the apparatus main assembly A, thecoupling 15150 and the drive shaft 180 engage with each other. Referringto FIG. 102 and FIG. 103, the description will be made with respect tothe engaging operation of this coupling 15150. FIG. 102 is a perspectiveview which illustrates the major parts of the drive shaft and drivingside of the cartridge. FIG. 103 is a longitudinal sectional view, asseen from the lower part of the apparatus main assembly.

In the mounting process of the cartridge B, as shown in FIG. 102, thecartridge B is mounted into the apparatus main assembly A in thedirection (the direction of the arrow X4) substantially perpendicular tothe axis L3. The axis L2 of the coupling 15150 inclines to thedownstream with respect to the mounting direction X4 relative to theaxis L1 beforehand (pre-engagement angular position) (FIG. 102 (a), FIG.103 (a)). By this inclination of the coupling 15150, with respect to thedirection of the axis L1, the free end position 15150A1 is closer to thephotosensitive drum 107 than the shaft free-end 180 b 3 with respect tothe direction of the axis L1. In addition, the free end position 15150A2is closer to the pin 182 than the shaft free-end 180 b 3 with respect tothe direction of the axis L1 (FIG. 103 (a)).

First, the free end position 15150A1 passes by the drive shaft free-end180 b 3. Thereafter, the driving shaft receiving surface 150 f ofconical shape or the driven projection 150 d contacts to the free endportion 180 b of the drive shaft 180, or the rotational force drivetransmission pin 182. Here, the receiving surface 150 f and/or theprojection 150 d are the contact portions of the cartridge side. Inaddition, the free end portion 180 b and/or the pin 182 are the engagingportions of the main assembly side. And, in response to the movement ofthe cartridge B, the coupling 15150 is inclined so that the axis L2becomes substantially co-axial with the axis L1 (FIG. 103 (c)). And,when the position of the cartridge B is finally determined relative tothe apparatus main assembly A, the drive shaft 180 and thephotosensitive drum 107 are substantially co-axial. More particularly,in the state of the contact portion of the cartridge side contactingwith the engaging portion of the main assembly side, in response to theinsertion toward the back side of the apparatus main assembly A of thecartridge B, the coupling 15150 is pivoted to the rotational forcetransmitting angular position from the pre-engagement angular position,so that the axis L2 becomes substantially co-axial with the axis L1.And, the coupling 15150 and the drive shaft 180 are engaged with eachother (FIG. 102 (b), FIG. 103 (d)).

As has been described hereinbefore, the coupling 15150 is mounted forinclining motion relative to the axis L1. And, it can be engaged withthe drive shaft 180 by the pivoting of the coupling 15150 correspondingto the mounting operation of the cartridge B.

In addition, similarly to Embodiment 1, the engaging operation of thecoupling 15150 described above can be carried out regardless of thephase of the drive shaft 180 and the coupling 15150.

In this manner, according to he present embodiment, the coupling 15150is mounted for revolving or whirling motion (swinging) around the axisL1 substantially. The motion illustrated in FIG. 103 may include thewhirling motion.

Referring to FIG. 104, the description will be made about the rotationalforce transmitting operation at the time of rotating the photosensitivedrum 107. The drive shaft 180 rotates with the drum driving gear 181 inthe direction of X8 in the Figure by the rotational force received fromthe motor 186. The gear 181 is a helical gear and the diameter thereofis the approx. 80 mm. And, the pin 182 integral with the drive shaft 180contacts to any two of receiving surfaces 150 e (four places)(rotational force receiving portions) of the coupling 15150. And, thecoupling 15150 rotates by the pin 182 pushing the receiving surface 150e. In addition, in the coupling 15150, the rotational force transmittingpin 15155 (coupling side engaging portion, rotational force transmittingportion) contacts to the rotational force transmission surface(rotational force receiving member) 15151 h 1, 15151 h 2. By this, thecoupling 15150 is coupled, for transmission of driving force, with thephotosensitive drum 107. Therefore, the photosensitive drum 107 rotatesthrough the flange 15151 by the rotation of the coupling 15150.

In addition, when the axis L1 and the axis L2 are deviated to a slightdegree, the coupling 15150 inclines a little. By this, the coupling15150 can rotate without applying large load to the photosensitive drum107 and the drive shaft 180. Therefore, at the time of assembling thedrive shaft 180 and the photosensitive drum 107, no precise adjustmentis necessary. Therefore, the manufacturing can be reduced.

Referring to FIG. 105, the description will be made as to thedismounting operation of the coupling 15150 at the time of taking outthe process cartridge B-2 from the apparatus main assembly A. FIG. 105is a longitudinal sectional view, as seen from the lower part of theapparatus main assembly. When the cartridge B is demounted from theapparatus main assembly A as shown in FIG. 105, it is moved in thedirection (the direction of the arrow X6) substantially perpendicular tothe axis L3. First, similarly to embodiment 1, at the time of demountingthe cartridge B-2, the drive transmission pin 182 of the drive shaft 180is positioned in any two of standing-by portions 15150 k 1-15150 k 4(Figure).

After the drive of the photosensitive drum 107 stops, the coupling 15150takes the rotational force transmitting angular position, wherein theaxis L2 is substantially co-axial with the axis L1. And, when thecartridge B moves toward the front side of the apparatus main assembly A(the dismounting direction X6), the photosensitive drum 107 is movedtoward the front side. In response to this movement, shaft receivingsurface 15150 f or the projection 15150 d in the upstream with respectto the dismounting direction of the coupling 15150 contacts at least tothe free end portion 180 b of the drive shaft 180 (FIG. 105a ). And, theaxis L2 begins (FIG. 105 (b)) to incline upstream with respect to thedismounting direction X6. This inclining direction is the same as theinclination of the coupling 15150 at the time of the mounting of thecartridge B. By the dismounting operation of this cartridge B, thecartridge B is moved while the upstream free end portion 15150 A3 withrespect to the dismounting direction X6 contacts to the free end portion180 b. And, the coupling 15150 is inclined until the upstream free endportion 15150 A3 reaches to the drive shaft free-end 180 b 3 (FIG. 105(c)). The angular position of the coupling 15150 in this case is thedisengaging angular position. And, in this state, the coupling 15150 ispassed by the drive shaft free-end 180 b 3, contacting with the driveshaft free-end 180 b 3 (FIG. 105 (d)). Thereafter, the cartridge B-2 istaken out of the apparatus main assembly A.

As has been described hereinbefore, the coupling 15150 is mounted forpivoting motion relative to the axis L1. And, the coupling 15150 can bedisengaged from the drive shaft 180 by the coupling 15150 pivotingcorrespondingly to the dismounting operation of the cartridge B-2.

The motion illustrated in FIG. 105 may include the whirling motion.

With the structure as described above, the coupling 15150 is integralpart of the photosensitive drum as the photosensitive drum unit.Therefore, at the time of the assembling, handling is easy and theassembling property is improved.

In order to incline the axis L2 to the pre-engagement angular positionimmediately before the coupling 15150 engages with the drive shaft 180,any one of structures of the embodiment 3-embodiment 9 is usable.

In addition, in this embodiment, it has been described that the drumflange of the driving side is a separate member from the photosensitivedrum. However, the present invention is not limited to such an example.In other words, the rotational force receiving portion may be directlyprovided on the cylindrical drum, not on the drum flange.

[Embodiment 18]

Referring to FIG. 106, FIG. 107, and FIG. 108, the 18th embodiment ofthe present invention will be described.

The present embodiment is a modified example of the coupling describedin Embodiment 17. The configurations of the drum flange and retainingmember of the driving side differ in Embodiment 17. In any case, thecoupling is pivotable in the given direction irrespective of the phaseof the photosensitive drum. In addition, the structure for mounting ofthe photosensitive drum unit to the second frame as will be describedbelow is the same as that of the foregoing embodiment, and therefore,the description is omitted.

FIGS. 106 (a) and (b) illustrate a first modified example of thephotosensitive drum unit. In FIGS. 106 (a) and (b), since thephotosensitive drum and the non-driving side drum flange are the same asthose of Embodiment 16, these are not illustrated.

More particularly, the coupling 16150 is provided with a supportingportion 16150 p of a ring shape which is pierced by the pin 155. Theedge lines 16150 p 1, 16150 p 2 of the peripheral part of the supportingportion 16150 p are equidistant from the axis of the pin 155.

And, an inner periphery of the drum flange (rotational force receivingmember) 16151 constitutes a spherical surface portion 16151 i (recess).A center of the spherical surface portion 16151 i is disposed on theaxis of the pin 155. In addition, a slot 16151 u is provided and this isthe hole which extends in the direction of the axis L1. By the provisionof this hole, the pin 155 is not interfered when the axis L2 inclines.

In addition, a retaining member 16156 is provided between the drivenportion 16150 a and the supporting portion 16150 p. And, the portionopposed to the supporting portion 16150 p is provided with the sphericalsurface portion 16156 a. Here, the spherical surface portion 16156 a isconcentric with the spherical surface portion 16151 i. In addition, aslot 16156 u is disposed so that it is continuous with the slot 16151 uin the direction of the axis L1. Therefore, when the axis L1 pivots, thepin 155 can move the inside of the slots 16151 u, 16156 u.

And, the drum flange, the coupling, and the retaining member for thesedriving side structures are mounted to the photosensitive drum. By this,the photosensitive drum unit is constituted.

With the structure as described above, when the axis L2 is inclined, theedge lines 16150 p 1, 16150 p 2 of the supporting portion 16150 p movealong the spherical surface portion 16151 i and the spherical surfaceportion 16156 a. By this, similarly to the foregoing embodiment, thecoupling 16150 can be inclined assuredly.

In this manner, the supporting portion 16150 p is pivotable relative tothe spherical surface portion 16151 i that is, the suitable gap isprovided between the flange 16151 and the coupling 16150, so that thecoupling 16150 is swingable.

Therefore, the effects similar to the effects described in Embodiment 17are provided.

FIGS. 107 (a) and (b) illustrate a second modified example of thephotosensitive drum unit. In FIGS. 107 (a) and (b), since thephotosensitive drum and the non-driving side drum flange are the same asthose of Embodiment 17, the illustration is omitted.

More particularly, similarly to Embodiment 17, a coupling 17150 isprovided with a spherical supporting portion 17150 p which has anintersection between axis of the pin 155, and axis L2 as the centersubstantially.

A drum flange 17151 is provided with a conical portion 17151 i contactedon the surface of the supporting portion 17150 p (recess).

In addition, a retaining member 17156 is provided between the drivenportion 17150 a and the supporting portion 17150 p. In addition, an edgeline portion 17156 a contacts with the surface of the supporting portion17150 p.

And, the structure (the drum flange, coupling, and retaining member) ofthis driving side is mounted to the photosensitive drum. By this, thephotosensitive drum unit is constituted.

With the structure as described above, when the axis L2 inclines, thesupporting portion 17150 p becomes movable along the conical portion17151 i and the edge line 17156 a of retaining member. By this, thecoupling 17150 can be inclined assuredly.

As described above, the supporting portion 17150 p is pivotable(swingable) relative to the conical portion 17151 i. Between the flange17151 and the coupling 17150, a gap is provided in order to permit thepivoting of the coupling 17150. Therefore, the effects similar to theeffects described in Embodiment 17 are provided.

FIGS. 108 (a) and (b) illustrate a third modified example of thephotosensitive drum unit U7. The photosensitive drum and the non-drivingside drum flange are the same as that of Embodiment 17 in the modifiedexample of FIGS. 108 (a) and (b), and therefore, the illustration isomitted.

More particularly, they are disposed co-axially with the rotation axisof a pin 20155. In addition, a coupling 20150 has a flat surface portion20150 r perpendicular to the axis L2. In addition, it is provided with asemi-spherical supporting portion 20150 p which has an intersectionbetween axis of a pin 20155 and the axis L2 as the center substantially.

The flange 20151 is provided with the conical portion 20151 i which hasan apex 20151 g on the axis thereof. The apex 20151 g is contacted withthe flat surface portion 20150 r of the coupling.

In addition, a retaining member 20156 is provided between the drivenportion 20150 a and the supporting portion 20150 p. In addition, an edgeline portion 20156 a contacts with a surface of the supporting portion20150 p.

And, the structure (the drum flange, coupling, and retaining member) ofthis driving side is mounted to the photosensitive drum. By this, thephotosensitive drum unit is constituted.

With the structure as described above, even if the axis L2 inclines, thecoupling 20150 and the flange 20151 are always in contact to each othersubstantially at the one point. Therefore, the coupling 20150 can beinclined assuredly.

As described above, the flat surface portion 20150 r of the coupling isswingable relative to the conical portion 20151 i. Between the flange20151 and the coupling 20150, in order to permit the swinging of thecoupling 17150, a gap is provided.

The effects described above can be provided by constituting thephotosensitive drum unit in this manner.

As means for inclining the coupling to the pre-engagement angularposition, any one of the structures of Embodiment 3 to the embodiment 9is used.

[Embodiment 19]

Referring to FIG. 109, FIG. 110, and FIG. 111, the 19th embodiment ofthe present invention will be described.

The point in which the present embodiment is different from Embodiment 1is the mounting structure of the photosensitive drum, and rotationalforce transmission structure from the coupling to the photosensitivedrum.

FIG. 109 is a perspective view which illustrates a drum shaft and acoupling. FIG. 111 is a perspective view of a second frame unit, as seenfrom the driving side. FIG. 110 is a sectional view taken along S20-S20of FIG. 111.

In this embodiment, the photosensitive drum 107 is supported by a drumshaft 18153 extended from a driving side of a second frame 18118 to anon-driving side thereof. By this, a position of the photosensitive drum107 can further accurately be determined. This will be described more inthe detail.

The drum shaft (rotational force receiving member) 18153 supports apositioning hole 18151 g, 18152 g of flanges 18151 and 18152 at theopposite ends of the photosensitive drum 107. In addition, the drumshaft 18153 rotates integrally with the photosensitive drum 107 by adrive transmitting portion 18153 c. In addition, the drum shaft 18153 isrotatably supported by the second frame 18118 through bearing members18158 and 18159 in the neighborhood of the opposite ends thereof.

A free end portion 18153 b of the drum shaft 18153 has the same asconfiguration as the configuration described with respect toEmbodiment 1. More particularly, the free end portion 18153 b has aspherical surface and its drum bearing surface 150 f of the coupling 150is slidable along the spherical surface. By doing so, the axis L2 ispivotable in any direction relative to the axis L1. In addition, thedisengagement of the coupling 150 is prevented by the drum bearingmember 18157. And, they are unified as the process cartridge byconnecting a first frame unit (unshown) with the second frame 18118.

And, the rotational force is transmitted from the coupling 150 through apin (rotational force receiving member) 18155 to the photosensitive drum107. The pin 18155 is through the center of the free end portion(spherical surface) 18153 of the drum shaft.

In addition, the coupling 150 is prevented by the drum bearing member18157 from disengagement.

The engagement and disengagement between the coupling and the apparatusmain assembly in interrelation with the mounting and dismountingoperations of the cartridge are the same as that of Embodiment 1, andtherefore, the description is omitted.

As for the structure for inclining the axis L2 toward the pre-engagementangular position, any one of the structures of the embodiment3-embodiment 10 is usable.

In addition, the structure described with respect to Embodiment 1 as tothe configuration at the free end of the drum shaft can be used.

In addition, as has been described with respect to Embodiment 1 (FIG.31), the inclining direction of the coupling relative to the cartridgeis regulated by the drum bearing member. By this, the coupling can bemore assuredly engaged with the drive shaft.

The structure will not be limited, if the rotational force receivingportion is provided to the end part of the photosensitive drum, and itrotates integrally with the photosensitive drum. For example, it may beprovided on the drum shaft provided at the end part of thephotosensitive drum (cylindrical drum) as has been described withrespect to Embodiment 1. Or, as has been described in this embodiment,it may be provided at the end part of the drum penetrating shaft whichis through the photosensitive drum (cylindrical drum). Furtheralternatively, as has been described with respect to Embodiment 17, itmay be provided on the drum flange provided at the end part of thephotosensitive drum (cylindrical drum).

The engagement (coupling) between the drive shaft and the coupling meansthe state where the coupling is abutted to or contacted to the driveshaft and/or the rotational force applying portion in addition, inaddition, it means that when the drive shaft in addition, starts therotation to the meaning, the coupling abuts to or contacts to therotational force applying portion and the rotational force can bereceived from the drive shaft.

In the embodiments described above, as for alphabetical sufixes of thereferential signs in the coupling, the same alphabetical sufixes areassigned to the members which have the corresponding functions.

FIG. 112 is a perspective view of a photosensitive drum unit U accordingto an embodiment of the present invention.

In the Figure, the photosensitive drum 107 is provided with a helicalgear 107 c at the end which has the coupling 150. The helical gear 107 ctransmits the rotational force which the coupling 150 receives from theapparatus main assembly A to the developing roller (process means) 110.This structure is applied to the drum unit U3 shown in FIG. 97.

In addition, the photosensitive drum 107 is provided with a gear 107 dat the end opposite from the end which has the helical gear 107 c. Inthis embodiment, this gear 107 d is a helical gear. The gear 107 dtransmits the rotational force which the coupling 150 receives from theapparatus main assembly A to the transfer roller 104 (FIG. 4) providedin the apparatus main assembly A.

In addition, the charging roller (process means) 108 contacts over thelongitudinal range to the photosensitive drum 107. By this, the chargingroller 108 rotates with the photosensitive drum 107. The transfer roller104 may be contacted to the photosensitive drum 107 over thelongitudinal range thereof. By this, the transfer roller 104 may berotated by the photosensitive drum 107. In this case, the gear for therotation of the transfer roller 104 is unnecessary.

In addition, as shown in FIG. 98, the photosensitive drum 107 isprovided with a helical gear 15151 c at the end which has the coupling15150. The gear 15151 c transmits the rotational force received by thecoupling 15150 from the apparatus main assembly A to the developingroller 110 and, with respect to the direction of the axis L1 of thephotosensitive drum 107, the position in which the gear 15151 c isprovided, and the position in which the rotational force transmittingpin (rotational force transmitting portion) 15150 h 1, h 2 is providedoverlap relative to each other (the overlapping position is shown by 3in FIG. 98).

In this manner, the gear 15151 c and the rotational force transmittingportion overlap relative to each other with respect to the direction ofthe axis L1. By this, the force tending to deform the cartridge frame B1is reduced. In addition, the length of the photosensitive drum 107 canbe reduced.

The couplings of the embodiments described above can apply to this drumunit.

Each coupling described above has the following structure.

The coupling (for example, the couplings 150, 1550, 1750, and 1850,3150.4150, 5150, 6150, 7150, 8150, 1350, 1450, 11150, 12150 12250 12350,13150, 14150, 15150, 16150, 17150, 20150, 21150, and so on) engages withthe rotational force applying portion (for example, the pins 182, 1280,1355, 1382, 9182 and so on) provided in the apparatus main assembly A.And, the coupling receives the rotational force for rotating thephotosensitive drum 107. In addition, this each coupling is pivotablebetween the rotational force transmitting angular position fortransmitting the rotational force for rotating the photosensitive drum107 by engaging with the rotational force applying portion to thephotosensitive drum 107, and the disengaging angular position inclinedin the direction away from the axis L1 of the photosensitive drum 107from the rotational force transmitting angular position. In addition, atthe time of demounting the cartridge B from the apparatus main assemblyA in the direction substantially perpendicular to the axis L1, thecoupling is pivoted from the rotational force transmitting angularposition to the disengaging angular position.

As described in the foregoing, the rotational force transmitting angularposition and the disengaging angular portion may be the same orequivalent to each other.

In addition, at the time of mounting the cartridge B to the apparatusmain assembly A, the operation is as follows. The coupling is pivotedfrom the pre-engagement angular position to the rotational forcetransmitting angular position in response to moving the cartridge B inthe direction substantially perpendicular to the axis L1, so as topermit the part of the coupling (for example, the portion at thedownstream free end position A1) positioned in the downstream withrespect to the direction in which the cartridge B is mounted to theapparatus main assembly A to circumvent the drive shaft. And, thecoupling is positioned at the rotational force transmitting angularposition.

The substantial perpendicularity has been explained hereinbefore.

The coupling member has a recess (for example 150 z, 12150 z, 12250 z,14150 z 15150 z, 21150 z) in which a rotational axis L2 the couplingmember extends through a center of the shape defining the recess. Therecess is over a free end of the driving shaft (for example, 180, 1180,1280 1380, 9180) in the state in which the coupling member is positionedat the rotational force transmitting angular position. The rotatingforce receiving portion (for example rotating force receiving surface150 e, 9150 e, 12350 e, 14150 e, 15150 e) is projected from a portionadjacent the driving shaft in the direction perpendicular to the axis L3and is engageable or abuttable to the rotating force applying portion inthe rotational direction of the coupling. By doing so, the couplingreceives the rotating force from the driving shaft thereby to rotate.When the process cartridge is dismounted from the main assembly of theelectrophotographic image forming apparatus, the coupling member pivotsfrom the rotational force transmitting angular position to thedisengaging angular position so that part (upstream end portion 150A3,1750A3, 14150A3, 15150A3 with respect to the dismounting direction) ofthe coupling member circumvents the driving shaft in response tomovement of the process cartridge in the direction substantiallyperpendicular to the axis of the electrophotographic photosensitivedrum. By doing so, the coupling is disengaged from the driving shaft.

A plurality of such rotational force receiving portions are provided ona phantom circle C1 (FIG. 8, (d), FIG. 95 (d)) having a center O (FIGS.8, (d), FIG. 95 (d)) on the rotational axis of the coupling member atpositions substantially diametrically opposite to each other.

The recess of the coupling has an expanding portion (for example, FIGS.8, 29, 33, 34, 36, 47, 51, 54, 60, 63, 69, 72, 82, 83, 90, 91, 92, 93,106, 107 108). A plurality of the rotational force receiving portionsare provided at regular intervals along a rotational direction of thecoupling member. The rotating force applying portion (for example, 182a, 182 b) is projected at each of two positions and is extended in thedirection perpendicular to the axis of the driving shaft. One of therotating force receiving portions is engaged to one of the two rotatingforce applying portions. The other one of the rotating force receivingportions which is opposed to the one of the rotating force receivingportion is engaged to the other one of the two rotating force applyingportions. By doing so, the coupling receives the rotating force from thedriving shaft thereby to rotate. With such a structure, the rotatingforce can be transmitted to the photosensitive drum by the coupling.

The expanding portion has a conical shape. The conical shape has an apexon the rotational axis of the coupling member, and in the state in whichcoupling member is positioned at the rotational force transmittingangular position, the apex is opposed to the free end of the drivingshaft. The coupling member is over the free end of the driving shaftwhen the rotational force is transmitted to the coupling member. Withsuch a structure, the coupling can engage (connect) with the drivingshaft projected in the main assembly of the apparatus with overlappingwith respect to the direction of axis L2. Therefore, the coupling canengage with the driving shaft with stability.

The free end portion of the coupling covers the free end of the drivingshaft. Therefore, the coupling may be easily disengaged from the drivingshaft. The coupling can receive the rotating force with high accuracyfrom the driving shaft.

The coupling having the expanding portion and therefore the drivingshaft can be cylindrical. Because of this, the machining of the drivingshaft is easy.

The coupling has the expanding portion of a conical shape, so thatabove-described effects can be enhanced.

When the coupling is in the rotational force transmitting angularposition, the axis L2 and the axis L1 are substantially coaxial. In thestate in which coupling member is positioned at the disengaging angularposition, the rotational axis of the coupling member is inclinedrelative to the axis of the electrophotographic photosensitive drum soas to permit an upstream portion of the coupling member passes by thefree end of the driving shaft in a removing direction in which theprocess cartridge is dismounted from the main assembly of theelectrophotographic image forming apparatus. The coupling memberincludes a rotating force transmitting portion (for example, 150 h, 1550h, 9150 h, 14150 h, 15150 h) for transmitting the rotating force to theelectrophotographic photosensitive drum, and a connecting portion (forexample, 7150 c between the rotating force receiving portion and therotating force transmitting portion, wherein the rotating forcereceiving portion, the connecting portion, the rotating forcetransmitting portion are arranged along the rotational axis direction.When the process cartridge is moved in the direction substantiallyperpendicular to the driving shaft, the pre-engagement angular positionis provided by the connecting portion contacting a fixed portion (guiderib (contact portion) 7130R1 a) provided in the main assembly of theelectrophotographic image forming apparatus.

The cartridge B comprises a maintaining member (locking member 3159,urging member 4159 a, 4159 b, locking member 5157 k, magnet member 8159)for maintaining the coupling member at the pre-engagement angularposition, wherein the coupling member is maintained at thepre-engagement angular position by a force exerted by the maintainingmember. The coupling is positioned at the pre-engagement angularposition by the force of the maintaining member. The maintaining membermay be an elastic member (urging member 4159 a, 4159 b). By the elasticforce of the elastic member, the coupling is maintained at theengagement angle position. The maintaining member may be a frictionmember (locking member 3159). By the frictional force of the frictionmember, the coupling is maintained at the engagement angle position. Themaintaining member may be a locking member (locking member 5157 k). Themaintaining member may be a magnetic member (portion 8159) provided onthe coupling. By the magnetic force of the magnetic member, the couplingis maintained at the engagement angle position.

The rotating force receiving portion is engaged with the rotating forceapplying portion which is rotatable integrally with the driving shaft.The rotating force receiving portion is engageable to the rotating forceapplying portion integrally rotatable with the driving shaft, whereinwhen the rotating force receiving portion receives the driving force forrotating the coupling member, and the rotating force receiving portionis inclined in a direction to receive a force toward the driving shaft.By the attracting force, the coupling is assured to contact the free endof the driving shaft. Then, the position of the coupling with respect tothe direction of axis L2 relative to the driving shaft. When thephotosensitive drum 107 is also attracted, the position of thephotosensitive drum 107 is determined relative to the main assembly ofthe apparatus with respect to the direction of the axis L1. The pullingforce may be properly set by one skilled in the art.

The coupling member is provided to an end of the electrophotographicphotosensitive drum and is capable of tilting relative to the axis ofthe electrophotographic photosensitive drum substantially in alldirections. By doing so, the coupling can pivot smoothly between thepre-engagement angular position and the rotational force transmittingangular position and between the rotational force transmitting angularposition and the disengaging angular position.

Substantially all directions is intended to mean that coupling can pivotto the rotational force transmitting angular position irrespective ofthe phase at which the rotating force applying portion stops.

In addition, the coupling can pivot to the disengaging angular positionirrespective of the phase at which the rotating force applying portionstops.

A gap is provided between the rotating force transmitting portion (forexample, 150 h, 1550 h, 9150 h, 14150 h, 15150 h) and the rotating forcereceiving member for example, pin 155, 1355. 9155, 13155, 15155, 15151h) so that coupling member is capable of tilting relative to the axis ofthe electrophotographic photosensitive drum substantially in alldirections, wherein the rotating force transmitting portion is providedat an end of the electrophotographic photosensitive drum and is movablerelative to the rotating force receiving member, and the rotating forcetransmitting portion and the rotating force receiving member areengageable to each other in a rotational direction of the couplingmember. The coupling is mounted to the end of the drum in this manner.The coupling is capable of inclination substantially in all directionsrelative to the axis L1.

The main assembly of the electrophotographic image forming apparatusincludes an urging member (for example, slider 1131) movable between anurging position and a retracted position retracted from the urgingposition. When the process cartridge is mounted to the main assembly ofthe electrophotographic image forming apparatus, the coupling membermoves to the pre-engagement angular position by being urged by anelastic force of the urging member restoring to the urging positionafter being temporarily retracted to the retracted position by beingcontacted by the process cartridge. With this structure, even if theconnecting portion is retarded by friction, the coupling can beassuredly pivoted to the pre-engagement angular position.

The photosensitive drum unit comprises the following structures. Thephotosensitive drum unit (U, U1, U3, U7, U13) is mountable to anddismountable from the main assembly of the electrophotographic imageforming apparatus in a direction substantial perpendicular with an axialdirection of the driving shaft. The drum unit has an electrophotographicphotosensitive drum having a photosensitive layer (107 b) at aperipheral surface thereof, the electrophotographic photosensitive drumbeing rotatable about an axis thereof. It also includes a coupling forengagement with the rotating force applying portion and for receivingthe rotating force for rotating the photosensitive drum 107. Thecoupling may have the structures described in the foregoing.

The drum unit is mounted into the cartridge. By the cartridge beingmounted to the main assembly of the apparatus, the drum unit may bemounted to the main assembly of the apparatus.

The cartridge (B, B2) has the following structures.

The cartridge is mountable to and dismountable from the main assembly ofthe apparatus in the direction substantial perpendicular to the axialdirection of the driving shaft. The cartridge comprises a drum having aphotosensitive layer (107 b) at a peripheral surface thereof, theelectrophotographic photosensitive drum being rotatable about an axisthereof. It further comprises process means actable on thephotosensitive drum 107 (for example, cleaning blade 117 a, chargingroller 108, and developing roller 100). It further comprises thecoupling for receiving the rotating force for rotating the drum 107through engagement with the rotating force applying portion. Thecoupling may have the structures described in the foregoing.

The electrophotographic image forming apparatus can be loaded by thedrum unit.

The electrophotographic image forming apparatus can be loaded by theprocess cartridge.

The axis L1 is an axis of rotation of the photosensitive drum.

The axis L2 is an axis of rotation of the coupling.

The axis L3 is an axis of rotation of the driving shaft.

The whirling motion is not a motion with which the coupling itselfrotates about the axis L2, but the inclined axis L2 rotates about theaxis L1 of the photosensitive drum, although the whirling here does notpreclude the rotation of the coupling per se about the axis L2 of thecoupling 150.

[Other Embodiments]

The mounting-and-demounting path extends in slanted or non-slantedup-down direction relative to the drive shaft of the apparatus mainassembly in the embodiment described above However, the presentinvention is not limited to such examples The embodiments can suitablybe applied to the process cartridge which can be mount and demounted inthe direction perpendicular to the drive shaft depending on thestructure of the apparatus main assembly, for example.

In addition, in the embodiment described above, although the mountingpath is rectilinear relative to the apparatus main assembly, the presentinvention is not limited to such an example For example, the mountingpath may be a combination of the straight lines, or it may be acurvilinear path.

In addition, the cartridges of the embodiment described above form themonochrome image However, the embodiments described above can suitablybe applied to the cartridges for forming the images (for example, twocolor images, three color images, or full-color and so on) of the pluralcolors by a plurality of developing devices.

In addition, the process cartridge described above includes anelectrophotographic photosensitive member and the at least one processmeans, for example Therefore, the process cartridge may contain thephotosensitive drum and the charging means as the process meansintegrally The process cartridge may contain the photosensitive drum andthe developing means as the process means in unification The processcartridge may contain the photosensitive drum and the cleaning means asthe process means integrally Further, the process cartridge may containthe photosensitive drum and the two process means or more integrally.

In addition, the process cartridge is mount and demounted by a userrelative to the apparatus main assembly Therefore, the maintenance ofthe apparatus main assembly is in effect carried out by the userAccording to the embodiments described above, relative to the apparatusmain assembly which is not provided with the mechanism for moving themain assembly side drum coupling member for transmitting the rotationalforce to the photosensitive drum in the axial direction thereof, theprocess cartridge is detachably mountable in the direction substantiallyperpendicular to the axis of the drive shaft And, the photosensitivedrum can be rotated smoothly In addition, according to the embodimentdescribed above, the process cartridge can be demounted from the mainassembly of the electrophotographic image forming device provided withthe drive shaft in the direction substantially perpendicular to the axisof the drive shaft.

In addition, according to the embodiment described above, the processcartridge can be mounted to the main assembly of the electrophotographicimage forming device provided with the drive shaft in the directionsubstantially perpendicular to the axis of the drive shaft In addition,according to the embodiment described above, the process cartridge ismountable and demountable in the direction substantially perpendicularto the axis of the drive shaft relative to the main assembly of theelectrophotographic image forming device provided with the drive shaft.

In addition, according to the coupling described above, even if it doesnot make the driving gear provided in the main assembly move in theaxial direction thereof, they are mountable and demountable relative tothe apparatus main assembly by the movement of the process cartridge inthe direction substantially perpendicular to the axis of the driveshaft.

In addition, according to the embodiment described above, in the driveconnecting portion between the main assembly and the cartridge, thephotosensitive drum can rotate smoothly as compared with the case of theengagement between gears.

In addition, according to the embodiment described above, the processcartridge is detachably mountable in the direction substantiallyperpendicular to the axis of the drive shaft provided in the mainassembly, and, simultaneously, the photosensitive drum can rotatesmoothly

In addition, according to the embodiment described above, the processcartridge is detachably mountable in the direction substantiallyperpendicular to the axis of the drive shaft provided in the mainassembly, and, simultaneously, the smooth rotation of the photosensitivedrum can be carried out.

As has been described hereinbefore, in the present invention, the axisof the drum coupling member can take the different angular positionsrelative to the axis of the photosensitive drum. The drum couplingmember can be engaged with the drive shaft in the directionsubstantially perpendicular to the axis of the drive shaft provided inthe main assembly by this structure In addition, the drum couplingmember can be disengaged from the drive shaft in the directionsubstantially perpendicular to the axis of the drive shaft The presentinvention can be applied to the process cartridge, theelectrophotographic photosensitive member drum unit, the rotationalforce transmitting portion (drum coupling member), and theelectrophotographic image forming device.

While the invention has been described with reference to the structuresdisclosed herein, it is not confined to the details set forth, and thisapplication is intended to cover such modification or changes as maycome within the purposes of the improvements or the scope of thefollowing claims.

This application claims priority from Japanese Patent Applications Nos.346190/2006 filed Dec. 22, 2006, 042665/2007 filed Feb. 22, 2007, and330303/2007 filed Dec. 21, 2007, which are hereby incorporated byreference.

What is claimed is:
 1. An image forming apparatus comprising: a processcartridge including: a casing, a photosensitive drum having an axis L1,the photosensitive drum being rotatably supported in the casing topermit rotation about the axis L1, and a coupling member having an axisL2, the coupling member including (i) a first end portion connected tothe photosensitive drum, (ii) a second end portion, and (iii) aconnecting portion connecting the first end portion and the second endportion, wherein the second end portion includes at least one pair ofprojections, with each of the projections including a facing portionthat faces the axis L2, each facing portion being open to the axis L2,and wherein a maximum dimension, in a direction perpendicular to theaxis L2, of at least a part of the connecting portion is smaller than adiameter of an imaginary circle that is tangent to the facing portionsof the projections, and wherein the coupling member is movable between afirst position in which the axis L2 of the coupling member is coaxialwith the axis L1 of the photosensitive drum, and a second position inwhich the axis L2 of the coupling member is inclined with respect to theaxis L1 of the photosensitive drum; a driving motor; a driving shaftengageable with the second end portion of the coupling member of theprocess cartridge and having a rotational axis L3; a guide portionconfigured to guide insertion of the process cartridge into the imageforming apparatus along a mounting direction that is substantiallyperpendicular to the rotational axis L3 of the driving shaft; and anurging member movable between an urging position and a retractedposition retracted from the urging position, wherein, when the processcartridge is mounted to the image forming apparatus, the coupling memberis inclined toward the driving shaft by the connecting portion of thecoupling member being urged by an elastic force of the urging memberrestoring to the urging position after being temporarily retracted tothe retracted position by being contacted by the coupling member.